- Work is in progress to shift the bias of the publication list from other areas to late Roman history, with emphasis on numismatics.edit
The date of birth of Constantine I is known to be the 27 February. Unfortunately, the year is uncertain. However, a unique coin held by the British Museum for almost 200 years has been suggested to celebrate Constantine’s 50th birthday.... more
The date of birth of Constantine I is known to be the 27 February. Unfortunately, the year is uncertain. However, a unique coin held by the British Museum for almost 200 years has been suggested to celebrate Constantine’s 50th birthday. The coin bears the legend PLVRA NATAL FEL, “May there be many happy birth[day]s”. If this coin could be accurately assigned to a bronze coin emission with a known date, the riddle may be solved. The portrait style of the coin points to the 320’s. During this decade Constantine’s portrait under- went a succession of changes enabling us – when we combine the iconography and the mint marks – to restrict possible dates of production of a particular coin to a few years or less. Now a second example of the PLVRA NATAL FEL type has surfaced. The authenticity of the BM coin has never been questioned, but examination of the actual specimen revealed that it is a forgery. The new example shows the same indications of manipulation, and it is concluded that it is also an old forgery. Both were produced using genuine coins, by grinding down the original reverse and creating a new reverse with wax and acid treat- ment. They cannot be used to deduce the year of birth of Constantine I, which remains uncertain. The methods used to produce these forgeries are discussed.
Research Interests: Ancient History, Roman History, Early Christianity, Late Roman Empire, Ancient Roman Numismatics, and 13 moreRoman numismatics, Constantine, Roman Imperial Coins, Roman imperial numismatics, Roman History, Late Antiquity; History of Christianity, Paleochristian and Late Antique Archaeology, Ancient Coin Forgeries, Monnaies romaines, Numismatic Forgeries, Roman History and Numismatic, Late Roman Numismatics, Fausse Monnaie Antique, and fausse monnaie
This study describes an important Roman double-sided imperial lead seal. The front bears the image of an emperor wearing a laureate helmet, flanked by a Chi-Rho and the legend AVG N. The bust is closely comparable to that of Constantine I... more
This study describes an important Roman double-sided imperial lead seal. The front bears the image of an emperor wearing a laureate helmet, flanked by a Chi-Rho and the legend AVG N. The bust is closely comparable to that of Constantine I on coins, and the presence of a both a Chi-Rho and Sol supports our identification of Constantine I. Two further lead seals are also presented, interpreted as showing the same emperor. The Chi-Rho first appeared in 312, and Sol disappeared from the coinage in 318 CE, indicating that the date of the seal is between 312 and 318. The helmeted bust of the emperor is most similar to coin depictions from c. 315, especially from Ticinum. The seal is of the type possibly used on money bags, and we tentatively suggest that the seal could have been produced and used during Constantine's stay in Ticinum in the autumn/winter 315 CE. The simultaneous presence of a Chi-Rho and Sol on a seal of Constantine I indicates that the Chi-Rho had not yet taken on the Christian meaning it took later. The seal also confirms the evidence from the coinage that several years after the introduction of the Chi-Rho, Constantine still favoured Sol as his comes. The seal is taken to indicate that the Chi-Rho was introduced as Constantine's personal victory sign, not as a strictly Christian symbol. Roman money bags are described, and the ubiquitous three protrusions seen are explained through a comparison with ancient wine skins.
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In AD 326, Constantine executed his son Crispus and his wife Fausta. A die study of the 5-6 months-long Providentiae bronze coin emission of Constantinopolis indicates that Crispus was eliminated early in the emission. Production possibly... more
In AD 326, Constantine executed his son Crispus and his wife Fausta. A die study of the 5-6 months-long Providentiae bronze coin emission of Constantinopolis indicates that Crispus was eliminated early in the emission. Production possibly ended with the elimination of Fausta, dated here to October or November on the basis of coinage from Ticinum. The 50% more coins for officinae A than for B may indicate the number of anvils in use, three in A and two in B. The die study identifies 301 obverse and 302 reverse dies, that is, equal numbers. The average working life of each die may have been surprisingly short, perhaps a few hours to a few days. The number of known coins and dies may indicate that coins struck for Crispus and Fausta were actively withdrawn after their deaths. This controversial conclusion is supported by several further examples showing a similar pattern.
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An enigmatic group of 1/24-pound silver multiples has long been thought to commemorate the vicennalia of Constantine Caesar in 336/337. This study adds the mint of Rome to the list of producing mints but removes Constantinopolis and... more
An enigmatic group of 1/24-pound silver multiples has long been thought to commemorate the vicennalia of Constantine Caesar in 336/337. This study adds the mint of Rome to the list of producing mints but removes Constantinopolis and Nicomedia. Six further mints produced these multiples: Treveri, Arelate, Lugdunum, Aquileia, Siscia, and Thessalonica. The date and issuer of the multiples can be deduced from the geographic area encompassing these seven mints. In 335 CE, Constantine I prepared for his succession by dividing his empire amongst his three remaining sons plus his nephew Dalmatius. Six of these mints were in areas under the authority of Constantine Caesar, either directly or through his inferred tutelage of Constans. The mint of Thessalonica was, however, in Macedonia which was allotted to Dalmatius. Following the murder of Dalmatius soon after the death of Constantine I, Constans received Thessalonica, in reality meaning that his guardian Constantine Caesar gained control of the city. As a result, all seven mints producing the multiples were controlled by Constantine Caesar during the three-month period between the murder of Dalmatius and the proclamation of the three remaining Caesars as Augusti on 9 September 337. After this date there were no Caesars and no Augustus controlled all mints producing the multiples. The production of the silver multiples can thus be pinpointed to the three-month interregnum period following the death of Constantine I and Dalmatius.
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The famous SPES PVBLIC (SP) coin of Constantine I was not a small, special emission but part of the regular coinage. A detailed study of all 45 known genuine SP coins is presented. Several die matches between SP coins and coins outside... more
The famous SPES PVBLIC (SP) coin of Constantine I was not a small, special emission but part of the regular coinage. A detailed study of all 45 known genuine SP coins is presented. Several die matches between SP coins and coins outside the type are described, and the original number of dies is calculated. The die matches prove conclusively that the SP coins were part of two regular 4-type bronze coin emissions, also including the types GLORIA ROMANORVM (GR), GLORIA EXERCITVS (GE), and LIBERTAS PVBLICA (LP). The first 4-type emission, with Constantine’s laureate head, was produced normally, but data indicates that the second emission, with diademed head, was interrupted shortly after its inception, and the SP type was discontinued, after which the emission was continued. Indications are presented for an active removal of SP coins in circulation. The two 4-type emissions are detailed. Also the dafne emissions are reviewed and re-organized. The analysis indicates that silver Emission 2 of Ramskold 2018a was produced after the second 4-type emission but before the start of the dafne coinage.
The four known contemporary SP imitations are described, as are 22 modern forgeries. The evolution of Constantine’s diadem is detailed. Most important, the first diadems to appear in the bronze coinage can be dated to the later part of Constantine’s return journey from his vicennial celebrations. None are earlier than early/mid 327, without exception. The importance of the tie loop for chronology is presented. Coin production features such as the centering mark and compass circles are described.
Numerous hypotheses for the purpose and message of the SPES PVBLIC coins are reviewed, but the evidence is inconclusive. The view is forwarded that the SP type cannot be seen isolated but must be analyzed as one of four related types in the two 4-type emissions of GR, GE, LP, and SP. These in turn must be considered in the light of the disastrous vicennial celebration journey, during which Constantine had his eldest son, his wife, his nephew and many others killed. After the murders, Constantine travelled very slowly back from Rome to Constantinople. He must have made sure that his position was not threatened, and he would have made plans for a different future. These were the circumstances when the SPES PVBLIC type was introduced.
All credible reports of the Chi-Rho and the staurogram from the time of Constantine are reviewed and the hypotheses for their origins are discussed. The earliest depictions of the Chi-Rho are found on two North African milestones, securely dated to October 312 – April 313. The SP coins of Constantine I have been regarded since the 1500s as proof of Constantine’s conversion to Christianity. Evidence is presented here that Constantine’s Chi-Rho was a victory sign which later took on a Christian significance. The reports of Chi-Rho’s from under the Basilica of St Peter and from the Domus Faustae, both in Rome, are rejected here. The earliest credible occurrences of the Chi-Rho in a Christian context are on a tombstone from 324, and in Porphyrius’ poem no. 8, dating from before 326.
The sign described by Lactantius was a staurogram. There is no evidence that the staurogram predates Constantine. Previous datings of the staurogram in papyri have been revised, the graffiti occurrence (if it exists) may be post-Constantinian, and the earliest occurrence on coins is from 336 CE.
The four known contemporary SP imitations are described, as are 22 modern forgeries. The evolution of Constantine’s diadem is detailed. Most important, the first diadems to appear in the bronze coinage can be dated to the later part of Constantine’s return journey from his vicennial celebrations. None are earlier than early/mid 327, without exception. The importance of the tie loop for chronology is presented. Coin production features such as the centering mark and compass circles are described.
Numerous hypotheses for the purpose and message of the SPES PVBLIC coins are reviewed, but the evidence is inconclusive. The view is forwarded that the SP type cannot be seen isolated but must be analyzed as one of four related types in the two 4-type emissions of GR, GE, LP, and SP. These in turn must be considered in the light of the disastrous vicennial celebration journey, during which Constantine had his eldest son, his wife, his nephew and many others killed. After the murders, Constantine travelled very slowly back from Rome to Constantinople. He must have made sure that his position was not threatened, and he would have made plans for a different future. These were the circumstances when the SPES PVBLIC type was introduced.
All credible reports of the Chi-Rho and the staurogram from the time of Constantine are reviewed and the hypotheses for their origins are discussed. The earliest depictions of the Chi-Rho are found on two North African milestones, securely dated to October 312 – April 313. The SP coins of Constantine I have been regarded since the 1500s as proof of Constantine’s conversion to Christianity. Evidence is presented here that Constantine’s Chi-Rho was a victory sign which later took on a Christian significance. The reports of Chi-Rho’s from under the Basilica of St Peter and from the Domus Faustae, both in Rome, are rejected here. The earliest credible occurrences of the Chi-Rho in a Christian context are on a tombstone from 324, and in Porphyrius’ poem no. 8, dating from before 326.
The sign described by Lactantius was a staurogram. There is no evidence that the staurogram predates Constantine. Previous datings of the staurogram in papyri have been revised, the graffiti occurrence (if it exists) may be post-Constantinian, and the earliest occurrence on coins is from 336 CE.
Research Interests: Christianity, Roman History, Early Christianity, Late Roman Empire, Roman numismatics and archaeology, and 11 moreAncient Roman Numismatics, Roman imperial history, Roman coins, Constantinople, Constantine, Roman Imperial Coins, Early Christian Archaeology, Paleochristian and Late Antique Archaeology, Later Roman Empire, Late Roman Coinage, and Christian symbolism
This study presents the first evidence for a millennium celebration of the foundation of Byzantion, the city re-named Constantinopolis by Constantine I. An emission of silver donatives consists of miliarense and siliquae carrying the... more
This study presents the first evidence for a millennium celebration of the foundation of Byzantion, the city re-named Constantinopolis by Constantine I. An emission of silver donatives consists of miliarense and siliquae carrying the letter M, interpreted here to stand for the 1,000 years celebration, dated here to 333/334 CE. Supplementing the author’s previous publications of the silver emissions produced for the inauguration of Constantinopolis in 330 CE, a complete revision of all other Constantinian silver emissions from the city is presented, based on the 199 specimens known today. A review is given of Constantine’s evolving hair style, which is an important chronological indicator. i.e. changes in hair style are followed from 330 to 335 CE in the five bronze coinage emissions of Rome, and a revision and new chronology of these emissions are given. Completing the revision of all silver emissions from Constantinopolis under Constantine I, evidence is presented for the four remaining groups: the NOB CAESS medallions are made of bronze, not silver; the Constantiniana dafne gold and silver specimens are all forgeries; the authenticity of the Hanniballianus silver is questionable; and the AVGVSTVS/CAESAR medallions are not from Constantinopolis, but some are from Rome. Finally, the reasons why Eusebius abruptly discontinued his Chronicles in 326 are discussed, and Jerome’s contributions 40 years later for the 276th Olympiad are identified.
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This study describes all 67 known specimens of Constantine I’s Felicitas Romanorum silver emissions, including fragments and forgeries. These donatives were introduced by Constantine in 323/324 CE and produced until 328/329 CE. Three... more
This study describes all 67 known specimens of Constantine I’s Felicitas Romanorum silver emissions, including fragments and forgeries. These donatives were introduced by Constantine in 323/324 CE and produced until 328/329 CE. Three series are defined, each showing the number of princes recognised at the moment. A chronology is established, showing that the type was struck at six mints with a total of ten emissions. We correlate these with Constantine’s itineraries and find that every emission from every minting city coincides with the proven or possible presence of Constantine. All evidence, including hoard data, indicates that these silver “coins” were in fact donatives given out by Constantine along the route. The weight of the Felicitas Romanorum first increased in steps but soon stabilized at c. 4.35g. We also present a survey of all silver issues struck under Constantine between 309 and the introduction of the miliarense in 323/324. They appear to show that Constantine experimented with different weights for the silver donatives before the miliarense was created. We survey the various types of miliarense produced through Constantine’s reign and show that he produced two further types of miliarense: the Virtus exercitus and the Gloria exercitus, and we compare these to the slightly heavier 4 standards type. Again, it appears likely that all of these types were produced as donatives when Constantine was in the minting city. We show that Constantine’s denomination continued to be struck for generations, and how – just like under Constantine - the reverse imagery changed according to circumstances, with the number of rulers figured under the arch reflecting the actual situation in the imperial college. We also survey the Felicitas Romanorum type under the emperors after Constantine, and we see how the post-Constantinian types Victoria Romanorum and Gloria Romanorum fit in the picture. We give weight data for all of the emissions, and we conclude that for 40 years or more, the weight of the miliarense, introduced by Constantine I, remained stable.
Research Interests: Ancient History, Roman History, Byzantine Studies, Late Antiquity, Roman numismatics and archaeology, and 6 moreAncient Roman Numismatics, Constantine, Ancient Rome, Flavian Dynasty, Constantine the Great, Constantine the Great, Roman Empire, Early Christianity, Constantine the Great, and Coinage of Constantine the Great
Summary: A die link study of all 124 traceable examples of Festival of Isis tokens from the reign of Constantine I is presented. The first Festival of Isis issues were struck in 306 CE under the second tetrarchy. After a break during... more
Summary: A die link study of all 124 traceable examples of Festival of Isis tokens from the reign of Constantine I is presented. The first Festival of Isis issues were struck in 306 CE under the second tetrarchy. After a break during Maxentius’ rule, Constantine revived the concept, and his reign produced a profusion of types. All were struck at the imperial mint of Rome, and all in the name of a member of the imperial houses, with no anonymous examples. Of the 124 known Constantinian specimens, 97 show Egyptian gods. They are die linked to 27 examples of three ‘fractions’: PRINCIPI IVVENTVTIS, VICTORIA CAESS, and VOTA VICENNALIOR. Almost all appear to be struck in bronze, not in brass as became the custom later. The majority are die linked to other specimens, and the three largest die linked groups include 24, 14, and 11 examples, respectively. Only ten tokens lack die links. There are in total 51 obverse dies and 50 reverse dies. Statistical analysis may indicate that some 60 % (95 % confidence interval 47 % – 73 %) of the original number of dies are known. Evidence for issues struck the following years is presented: 313 – Rome in Constantine’s hands; 314 – reason unknown; 316 – decennalia; 317 – Caesars introduced; 321 – quinquennalia, 326 – vicennalia; 329 – visit by Constantine; 330/331 – quinvicennalia. The material thus forms a minimum of eight issues, but in a few cases, tokens may have been produced for both the opening and closing of the celebratory years, and the number could be up to ten. The early issues were produced in two to three sizes compatible with the regular coinage, but after 317 all tokens are small (approx. 15 mm, 1.5 g). No tokens are known from Constantine’s tricennalia, and it was only after his death that Festival of Isis tokens were produced again. The links to the 5-year celebrations show that the tokens were part of Constantine’s official propaganda. They were not an attempt by pagans in Rome to promote traditional religion.
Sample pages from the paper will be uploaded soon.
Sample pages from the paper will be uploaded soon.
Research Interests: Ancient Egyptian Religion, Ancient History, Roman History, Early Christianity, Byzantine Studies, and 10 moreLate Antiquity, Ancient numismatics (Archaeology), Roman numismatics and archaeology, Ancient Roman Numismatics, Isis Cult, Constantine, Isis in the Roman world, Coin Die-Study, Anubis, and Cult of Isis In the Roman World
The most discussed and controversial of all ancient bronze coins is the so called Pannonian cap coin, discovered in 2003, showing Constantine I wearing a pillbox cap. We have examined every detail of this coin through stereoscopic wet and... more
The most discussed and controversial of all ancient bronze coins is the so called Pannonian cap coin, discovered in 2003, showing Constantine I wearing a pillbox cap. We have examined every detail of this coin through stereoscopic wet and dry study, physical probing, iconographical analysis, die matching, and two types of radiological analyses: XEDS and micro-CT scanning. Each individual way of investigation indicates that the coin is ancient, and we are confident that it was produced in 318-319 CE. It shares the obverse die with a second Cap coin, discovered in 2012, which is thus also ancient. We identify the reverse die of the 2003 coin as engraved by an Imperial Mint engraver, and since the two coins share the same obverse die, it is likely but not certain that they were produced at the Imperial Mint of Siscia. Nor is it certain that they were officially sanctioned. We show that headgear seen on early 4th C art - including the porphyry tetrarchs in Venice and Niš; the Arch of Constantine; the great hunt mosaic in the Roman villa at Piazza Armerina; and on numerous palaeochristian sarcophagi - conventionally identified as the “Pannonian cap” of Vegetius, is in fact the headgear of the lictors – the state-paid summoners - at the time. We accordingly identify the pillbox cap on the two coins as that of a lictor.
Research Interests: Ancient History, Roman History, Late Antique and Byzantine History, Early Christianity, Byzantine Studies, and 12 moreLate Antiquity, Early Christian Apocryphal Literature, Ancient numismatics (Archaeology), X-Ray Fluorescence (XRF) Spectroscopy, Early Christian Art, Ancient Textiles, Ancient Roman Numismatics, Constantine, Early Christian Archaeology, Ancient Coin Forgeries, CT scanning, and Roman Archaeology
Combining numismatic and epigraphic evidence, Constantine’s vicennial celebration journey from Nicomedia to Rome is reconstructed. Donatives were produced on each major stop along the way. Newly discovered dynastic bronzes struck in Rome... more
Combining numismatic and epigraphic evidence, Constantine’s vicennial celebration journey from Nicomedia to Rome is reconstructed. Donatives were produced on each major stop along the way. Newly discovered dynastic bronzes struck in Rome on Constantine’s arrival include Crispus, which shows that the caesar still was alive. The subsequent issue struck in Rome, before Constantine’s departure, lacks Crispus. The caesar thus fell from grace during the vicennial celebrations in Rome in July-August 326. The study identifies and defines all major vicennial celebration issues struck by Constantine. The illustrated examples include 38 gold solidi and multiples, 12 siliquae, 29 dynastic bronzes, and several forgeries.
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""Two related types of silver medallions appear to have been struck for the dedication of Constantinople on 11 May 330 A.D. The first, whose reverse depicts a seated figure of Constantinopolis, has been widely catalogued in numismatic... more
""Two related types of silver medallions appear to have been struck for the dedication of Constantinople on
11 May 330 A.D. The first, whose reverse depicts a seated figure of Constantinopolis, has been widely catalogued in numismatic literature.1 The second, whose reverse depicts the Dea Roma, has not. This article presents a catalogue of the known exemplars of both types: 15 of the first and 3 of the second. It proposes that these were struck to imitate the tetradrachms of Hellenistic rulers. This conclusion is based on six factors: 1) the average weight and module match those of Hellenistic tetradrachms; 2) the medallion is struck in silver; 3) the thickness and high relief mirror those of tetradrachms; 4) the obverse is anepigraphic with the head cropped high on the neck; 5) the format of the reverse legend is typical of tetradrachms, and the image of Tyche was common on them; 6) Constantine wears a diadem, a revival of a royal accoutrement typical of Hellenistic monarchs. In addition, the argument will be made that these issues constitute something of a
brief return to the tradition of civic coinage.
This is argued first because civic coinages, including the coins of Roman imperial Byzantium, regularly represent city Tychai, and secondly, because this type appears to have been issued only from the mint of a single city,
a highly unusual restriction in the fourth century AD. The medallion can be viewed as valuable iconographic evidence for the cult of Constantinople’s Tyche established by Constantine and of his interest in maintaining Hellenic religious traditions and promoting his new capital as a second Rome.""
11 May 330 A.D. The first, whose reverse depicts a seated figure of Constantinopolis, has been widely catalogued in numismatic literature.1 The second, whose reverse depicts the Dea Roma, has not. This article presents a catalogue of the known exemplars of both types: 15 of the first and 3 of the second. It proposes that these were struck to imitate the tetradrachms of Hellenistic rulers. This conclusion is based on six factors: 1) the average weight and module match those of Hellenistic tetradrachms; 2) the medallion is struck in silver; 3) the thickness and high relief mirror those of tetradrachms; 4) the obverse is anepigraphic with the head cropped high on the neck; 5) the format of the reverse legend is typical of tetradrachms, and the image of Tyche was common on them; 6) Constantine wears a diadem, a revival of a royal accoutrement typical of Hellenistic monarchs. In addition, the argument will be made that these issues constitute something of a
brief return to the tradition of civic coinage.
This is argued first because civic coinages, including the coins of Roman imperial Byzantium, regularly represent city Tychai, and secondly, because this type appears to have been issued only from the mint of a single city,
a highly unusual restriction in the fourth century AD. The medallion can be viewed as valuable iconographic evidence for the cult of Constantinople’s Tyche established by Constantine and of his interest in maintaining Hellenic religious traditions and promoting his new capital as a second Rome.""
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Research Interests: Ancient History, Roman History, Byzantine Studies, Late Antiquity, Ancient numismatics (Archaeology), and 6 moreAlexander the Great, Ancient Roman Numismatics, Constantinople, Constantine, Ancient Rome, Flavian Dynasty, Constantine the Great, and Constantine the Great, Roman Empire, Early Christianity
Research Interests: Early Christianity, Byzantine Studies, Late Antiquity, Forgery, Fakery, Fraud, Christian Iconography, and 8 moreAncient Roman Numismatics, Constantinople, Constantine, Ancient Coin Forgeries, Ancient Rome, Flavian Dynasty, Constantine the Great, Constantine the Great, Roman Empire, Early Christianity, Forgery Detction, and Forgeries, fakes
The Lower Cambrian Chengjiang fauna is reviewed and shown to be closely comparable with the younger Burgess Shale fauna. but with various differences in detail. A diverse group of more or less annulated lobopod animals including ‘armoured... more
The Lower Cambrian Chengjiang fauna is reviewed and shown to be closely comparable with the younger Burgess Shale fauna. but with various differences in detail. A diverse group of more or less annulated lobopod animals including ‘armoured lobopods’ are regarded as representatives of the phylum Onychophora. ‘Trilobitomorphs’ include several new types. Probable protaspides of the trilobitomorph Naraoia are described. No molluscs or deuterostomes have been identified. The preservational orientations of the various taxa are reviewed and compared with orientations of the Burgess Shale taxa. Orientation in the sediment is found to be closely correlated to the original shape of individuals. Several new genera and species are described: the segmented. worm-shaped Yunnanozoon lividum gen. et sp.n., the ‘armoured lobopods’ Onychodictyon ferox gen. et sp.n. and Cardiodictyon catenulum gen. et sp.n. and the arthropods Saperion glumaceum gen. et sp.n., Sinoburius Iunaris gen. et sp.n., and Xandarella spectaculum gen. et sp.n.
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THERE is much interest in the early evolution of metazoans with the restudy of the Middle Cambrian 'soft-bodied' fauna of the Burgess Shale1. Several other, newly discovered Cambrian 'soft-bodied' faunas2 provide a wealth of new data. One... more
THERE is much interest in the early evolution of metazoans with the restudy of the Middle Cambrian 'soft-bodied' fauna of the Burgess Shale1. Several other, newly discovered Cambrian 'soft-bodied' faunas2 provide a wealth of new data. One of the oldest and best-preserved faunas was discovered in 1984 in Chengjiang in southern China3. This fauna is of early Cambrian age, about late Atdabanian4 (~520–530 Myr BP)2. We now describe a new 'armoured lobopod' from the Chengjiang fauna. This animal shows close affinity with the enigmatic Microdictyon 5. The conundrum Halludgenia 6 is reinterpreted as another 'armoured lobopod', as are Xenusion7 and Luolishania 8. The large plates set in pairs along the trunk are a synapomorphy of this group, which flourished soon after the 'Cambrian explosion'. Soft-part anatomy suggests that the group has affinities with the Burgess Shale 'lobopod' Aysheaia 9. All these marine, Cambrian forms are here grouped with the extant, terrestrial velvet worms in the phylum Onychophora.
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Marine animals related to Recent onychophorans form a significant component in Cambrian faunas. Twelve characters are analysed for homologies in the seven best known Cambrian onychophorans. New morphological evidence and homology analyses... more
Marine animals related to Recent onychophorans form a significant component in Cambrian faunas. Twelve characters are analysed for homologies in the seven best known Cambrian onychophorans. New morphological evidence and homology analyses for several characters indicate an anteroposterior reversal of Hallucigenia and Microdictyon. Proposed expansion of the trunk in Microdictyon during compaction is rejected. A jaw is tentatively identified in Onychodictyon. The shape of the annulations and the disposition of the tenth leg pair in Aysheaia are reinterpreted, and the suggestion of two somites to the first appendage pair is rejected. A suggested morphocline may mirror the phylogeny of the group. The taxonomic confusion surrounding the supposed radiolarian family Eoconchariidae is cleared.
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The exoskeleton in the Middle Cambrian Burgess Shale arthropod Tegopelte has previously been described as divided into tergites. Evidence from its sister taxon Saperion and from a Naraoia specimen from the Lower Cambrian Chengjiang fauna... more
The exoskeleton in the Middle Cambrian Burgess Shale arthropod Tegopelte has previously been described as divided into tergites. Evidence from its sister taxon Saperion and from a Naraoia specimen from the Lower Cambrian Chengjiang fauna enables a reinterpretation of the suggested tergite boundaries in Tegopelte as preservational artefacts. They are considered here as folds that were formed during flattening of the undivided dorsal shield. As in the Naraoia specimen, the folds were initiated in the axial region between appendage pairs and then continue laterally. In Tegopelte and Saperion, segmentally arranged furrows in the axial region facilitated fold formation. Characters other than presence of thoracic tergites and pygidium must be used to assess the affinities of Tegopelte, Arthropoda, Tegopeltidae, tagmosis, segmentation, Chengjiang fauna, Burgess Shale.
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New interpretations are available from recently published appendages of Eoredlichia intermedia (Early Cambrian Chengjiang fauna), the most primitive trilobite for which appendages are known. The basis (formerly identified as the coxa) is... more
New interpretations are available from recently published appendages of Eoredlichia intermedia (Early Cambrian Chengjiang fauna), the most primitive trilobite for which appendages are known. The basis (formerly identified as the coxa) is preserved in one appendage. An allegedly long proximal podomere in the endopod is actually subdivided into two and, at least in posterior appendages, each of these podomeres bears a strong, angular endite. The large, subquadrate basis, angular endite on the first podomere of the endopod, and attachment of the exopod along the whole length of the basis are features shared with naraoiids, for which Naraoia longicaudata Zhang & Hou is exemplar. The long line of attachment of the exopod to the basis works as a hinge joint in E. intermedia and is a feature shared by Olenoides serratus. This joint allows rotation of the basis and endopod around the hinge line, permitting extensive leg movement without forcing the large exopod fan out of position. The shape of the basis in O. serratus is reinterpreted here, and a new reconstruction of the exopod shows detailed similarity to E. intermedia. The limbs of Eoredlichia show that appendage structure in primitive trilobites is little altered from shared ancestry with naraoiids.
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"A temporary exposure of Middle Llandovery (Aeronian) shales in the Swedish town of Motala has yielded a rich collection of shelly fauna and graptolites. The shelly fauna is restricted to a thin mudstone band in a graptolitic shale... more
"A temporary exposure of Middle Llandovery (Aeronian) shales in the Swedish town of Motala has yielded a rich collection of shelly fauna and graptolites. The shelly fauna is restricted to a thin mudstone band in a graptolitic shale sequence, and is within the convolutus Biozone. This mudstone band may be correlated with a similar mudstone in the Kolka core from northwestern Latvia. The faunas, including the trilobites, from the two occurrences represent the same species. In the collection from Motala, nine species of trilobites are present, of which Acernaspis dispersa sp. nov. is new. The material represents the first trilobite fauna described from the Middle Llandovery of Sweden.
Ein temporärer Aufschluß von Schiefertonen des Mittleren Llandovery (Aeronium) in der schwedischen Stadt Motala erbrachte eine reiche Ausbeute an schalentragender Fauna und an Graptolithen. Die schalentragende Fauna ist auf eine dünne tonige Siltstein-Lage innerhalb einer Graptolithenschieferabfolge beschränkt und liegt innerhalb der convolutus Biozone. Diese Siltsteinlage läßt sich möglicherweise mit einer ähnlichen Lage im Kolka Bohrkern aus dem nordwestlichen Litauen korrelieren. Die Fauna, einschließlich der Trilobiten, der beiden Vorkommen ist identisch. Die Aufsammlungen von Motala enthalten neun Trilobitenarten, darunter Acernaspis dispersa sp.nov. Das Material stellt die erste Trilobitenfauna dar, die aus dem mittleren Llandovery von Schweden beschrieben worden ist."
Ein temporärer Aufschluß von Schiefertonen des Mittleren Llandovery (Aeronium) in der schwedischen Stadt Motala erbrachte eine reiche Ausbeute an schalentragender Fauna und an Graptolithen. Die schalentragende Fauna ist auf eine dünne tonige Siltstein-Lage innerhalb einer Graptolithenschieferabfolge beschränkt und liegt innerhalb der convolutus Biozone. Diese Siltsteinlage läßt sich möglicherweise mit einer ähnlichen Lage im Kolka Bohrkern aus dem nordwestlichen Litauen korrelieren. Die Fauna, einschließlich der Trilobiten, der beiden Vorkommen ist identisch. Die Aufsammlungen von Motala enthalten neun Trilobitenarten, darunter Acernaspis dispersa sp.nov. Das Material stellt die erste Trilobitenfauna dar, die aus dem mittleren Llandovery von Schweden beschrieben worden ist."
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"Eine Gruppe von Encrinurinae (Trilobiten) aus dem späten Llandovery und ausnahmsweise frühesten Wenlock des Baltikums, der Britischen Inseln und Kanadas wird als monophyletisch erkannt und mit dem Gattungsnamen Wallacia Lamont 1978... more
"Eine Gruppe von Encrinurinae (Trilobiten) aus dem späten Llandovery und ausnahmsweise frühesten Wenlock des Baltikums, der Britischen Inseln und Kanadas wird als monophyletisch erkannt und mit dem Gattungsnamen Wallacia Lamont 1978 belegt. Wallacia wird als Schwestergruppe von Encrinurus sensu stricto betrachtet. Eine Revision der Arten von Gotland führt zur Ausscheidung von W. laevis (Angelin 1851) aus den Oberen Visby-Schichten, sowie von W. jaanussoni n. sp. und W. masterleei n. sp. aus den Unteren Visby-Schichten. Auf siebzehn Merkmale beruhende Cladogramme der zehn benannten Arten von Wallacia zeigen W. masterleei und W. laevis als die nächsten Verwandten einer Gruppe aus dem Telychium Kanadas, zu der W. elegantula (Billings 1866), W. chattertoni n. sp. und W. hypolepra (Stearn 1956) gehören.
A group of late Llandovery and, exceptionally, earliest Wenlock encrinurine trilobites from the Baltic area, the British Isles, and Canada, is recognized as monophyletic. The generic name Wallacia Lamont 1978 is available for this group. Wallacia is regarded as sister taxon to Encrinurus sensu stricto. A systematic revision of species from Gotland recognizes W. laevis (Angelin 1851), from the Upper Visby Beds, and W. jaanussoni n. sp. and W. masterleei n. sp. from the Lower Visby Beds. Cladograms based on seventeen characters for the ten named species of Wallacia place W. masterleei and W. laevis as the closest relatives of a Canadian Telychian clade that includes W. elegantula (Billings 1866), W. chattertoni n. sp., and W. hypolepra (Stearn 1956)."
A group of late Llandovery and, exceptionally, earliest Wenlock encrinurine trilobites from the Baltic area, the British Isles, and Canada, is recognized as monophyletic. The generic name Wallacia Lamont 1978 is available for this group. Wallacia is regarded as sister taxon to Encrinurus sensu stricto. A systematic revision of species from Gotland recognizes W. laevis (Angelin 1851), from the Upper Visby Beds, and W. jaanussoni n. sp. and W. masterleei n. sp. from the Lower Visby Beds. Cladograms based on seventeen characters for the ten named species of Wallacia place W. masterleei and W. laevis as the closest relatives of a Canadian Telychian clade that includes W. elegantula (Billings 1866), W. chattertoni n. sp., and W. hypolepra (Stearn 1956)."
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New material of early growth stages of the Silurian (Llandovery) trilobite Acernaspis is described. Pre-adult ontogenetic stages of this genus closely resemble adults of the post-Llandovery genus Ananaspis. A heterochronic descent of... more
New material of early growth stages of the Silurian (Llandovery) trilobite Acernaspis is described. Pre-adult ontogenetic stages of this genus closely resemble adults of the post-Llandovery genus Ananaspis. A heterochronic descent of Ananaspis from Acernaspis is proposed. Ananaspis is interpreted as paedomorphic, having arisen largely through neoteny. Neotenic changes already appear in the lineage in the last Acernaspis species, and Ananaspis then underwent continuous neotenic change throughout its known Silurian history. ▭ Heterochrony, neoteny, Silurian, Trilobita, Phacopidae, Acernaspis. Ananaspis.
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Abstract: A data matrix of 32 characters, with a total of 132 character states and 48 terminal taxa of phacopid trilobites, was analysed using parsimony. The 108 most parsimonious trees have a length of 301 steps and a consistency index... more
Abstract: A data matrix of 32 characters, with a total of 132 character states and 48 terminal taxa of phacopid trilobites, was analysed using parsimony. The 108 most parsimonious trees have a length of 301 steps and a consistency index of 0.29. Two major clades were found, one including species referred to Acernaspis and one with species referred to Ananaspis, Paciphacops, Viaphacops, and Phacops. Most homoplasy occurs between the major clades of the trees, rather than within them. The major clades were also analysed separately, resulting in trees with significantly higher consistency indices. We redefine the following supraspecific taxa to make them monophyletic: Acernaspis, Ananaspis, and Paciphacops. In addition, Kainops, new genus, is described for a clade consisting of six taxa previously assigned to Ananaspis and Paciphacops. The evolutionary pattern resulting from our cladogram is compared with the approaches of Campbell and Eldredge, and it is argued that some of the assumptions made by these authors regarding the phylogeny of the group are not valid. The biogeography of the group was also analysed. It is found that phacopids from the Ludlow and older strata are distributed globally, with an emphasis, perhaps due to a large number of suitable localities, on Northern Europe. However, the lineage of phacopines leading up to Phacops is, with some slight exceptions, basically confined to the United States, being entirely absent in Northern Europe. The main phacopine lineage does not re-establish itself geographically until the middle Devonian. Finally, we analysed the evidence for polymorphism in phacopid trilobites, and reject this hypothesis on the basis of stratigraphy and the present cladogram.
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Nonhealing periradicular pathosis associated with endodontically treated teeth is customarily managed by revision (retreatment). Root-end resection is less often the first choice of treatment. Objectives. This prospective randomized study... more
Nonhealing periradicular pathosis associated with endodontically treated teeth is customarily managed by revision (retreatment). Root-end resection is less often the first choice of treatment. Objectives. This prospective randomized study compared the outcome of retreatment and surgical intervention in root canal treated teeth with nonhealing periradicular pathosis. Study design. One such tooth from each of 38 patients was randomly allotted to retreatment or root-end resection and root-end filling. Treatment outcome after 1 year was evaluated and compared clinically and radiographically. Results. The success rate for surgery was higher than for conventional retreatment, but the difference was not statistically significant. Conclusions. For management of nonhealing periradicular pathosis associated with root canal treated teeth, surgical intervention should be considered as an alternative to retreatment. In cases with a similar prognosis for both modes of treatment, the choice should be governed by consideration of intrinsic and extrinsic factors.
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Objective. Surgical management is intended to eliminate or block infection originating in the root canals. The root end is customarily sealed to prevent pathogenic products remaining in the root canal from reaching the periradicular... more
Objective. Surgical management is intended to eliminate or block infection originating in the root canals. The root end is customarily sealed to prevent pathogenic products remaining in the root canal from reaching the periradicular tissues. The purpose of this study was to evaluate the microbiologic and radiographic outcomes of surgical treatment of periradicular pathosis associated with teeth with necrotic pulps. Study Design. One tooth from each of 10 patients was root-end resected and root-end filled without prior root canal treatment. One year postoperatively, the outcomes were assessed radiographically and the root canals were sampled for bacteria. Results. Radiographic examination showed complete or incomplete (scar tissue) healing in 5 teeth and uncertain healing in the other 5 teeth. Bacteriologic samples from the root canals were positive in 9 of the 10 cases. Conclusions. In teeth with necrotic pulps, treatment of periradicular pathosis by surgery and root-end filling may show radiographic evidence of satisfactory healing 1 year postoperatively. However, viable bacteria may persist in the canals, constituting a potential risk factor for recurrence of periradicular pathosis. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999; )
Research Interests: Dentistry, Treatment Outcome, Humans, Female, Oral Surgery, and 15 moreMale, Root Canal Treatment, Follow-up studies, Risk factors, Aged, Middle Aged, Periapical Granuloma, Radicular Cyst, Adult, Root Canal, Study design, Dental Pulp Cavity, Retrograde Obturation, Risk Factors, and Surgical Treatment
The microleakage of four retrograde filling materials was compared in vitro. Fifty-three single rooted teeth were instrumentated and root filled with resin chloroform and gutta-percha. The gutta-percha cones were left extruding from the... more
The microleakage of four retrograde filling materials was compared in vitro. Fifty-three single rooted teeth were instrumentated and root filled with resin chloroform and gutta-percha. The gutta-percha cones were left extruding from the access opening. All teeth were apicected and retrograde fillings placed. The materials used were a non γ2 amalgam (Amalcap), a glass ionomer cement (ChemFil II), threaded titanium pins cemented with a glass ionomer cement (ChemFil II) and identical titanium pins cemented with a silicone material (Adheseal). After removal of the gutta-percha with tweezers, a radioactive isotope solution was placed in the teeth. Extraradicular samples were taken at 3, 7, 28, 77 and 104 days. All retrograde fillings showed some microleakage. The group with titanium pins cemented with silicone showed the least leakage: significantly less than the teeth with glass ionomer cement (P < 0.01) and with amalgam (P < 0.01). No significant differences were found between other groups.
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- Preserved ancient dies indicate a shift around 300CE from bronze dies to iron/steel dies. It is usually not possible in the coins to see what metal the die was made from. - The die metal may have differed between obverse and reverse... more
- Preserved ancient dies indicate a shift around 300CE from bronze dies to iron/steel dies. It is usually not possible in the coins to see what metal the die was made from.
- The die metal may have differed between obverse and reverse dies, as indicated by die clashing, but other explanations may be found.
- Magnifying lenses were known and were perhaps used for engraving the finest features but were probably not needed for engraving dies for standard coins.
- There is no evidence for the use of hubs or piece-punches in official coinage, not even for individual letter-punches.
- Only large features were gouged whereas most details – including the legends – were punched.
- The emperor's face received much more care in execution, especially smoothing, than other features.
- There was one set of punches for the legends and another for the central theme, possibly indicating different engravers.
- The legends were always engraved in reading direction, indicating that the engravers were literate.
- The die metal may have differed between obverse and reverse dies, as indicated by die clashing, but other explanations may be found.
- Magnifying lenses were known and were perhaps used for engraving the finest features but were probably not needed for engraving dies for standard coins.
- There is no evidence for the use of hubs or piece-punches in official coinage, not even for individual letter-punches.
- Only large features were gouged whereas most details – including the legends – were punched.
- The emperor's face received much more care in execution, especially smoothing, than other features.
- There was one set of punches for the legends and another for the central theme, possibly indicating different engravers.
- The legends were always engraved in reading direction, indicating that the engravers were literate.
Research Interests: Ancient History, Archaeology, Classical Archaeology, Roman History, Ancient numismatics (Archaeology), and 11 moreAncient Technology (Archaeology), Roman numismatics and archaeology, Ancient Roman Numismatics, Ancient Metal Technology, Engraved gems, Ancient Metallurgy, Constantine, Engraving, Ancient Studies, Ancient Coin Production Technology, and Roman Archaeology
Talk presented in 2015 at the Symposium Niš & Byzantium XIV, Niš, Serbia. The full results of this research was published in 2016 as “Methods for Authenticating Ancient Bronze Coins: A Case Study of Constantine's "Pannonian Cap" Coin”.... more
Talk presented in 2015 at the Symposium Niš & Byzantium XIV, Niš, Serbia.
The full results of this research was published in 2016 as “Methods for Authenticating Ancient Bronze Coins: A Case Study of Constantine's "Pannonian Cap" Coin”. The paper is available here on Academia.edu as the first paper listed above.
The full results of this research was published in 2016 as “Methods for Authenticating Ancient Bronze Coins: A Case Study of Constantine's "Pannonian Cap" Coin”. The paper is available here on Academia.edu as the first paper listed above.
Festival of Isis tesserae were first struck in 306. Constantine re-introduced Festival of Isis tesserae for New Year 313 immediately after defeating Maxentius and taking Rome. Constantine issued tesserae annually 313 – 318. Post-318... more
Festival of Isis tesserae were first struck in 306.
Constantine re-introduced Festival of Isis tesserae for New Year 313 immediately after defeating Maxentius and taking Rome.
Constantine issued tesserae annually 313 – 318. Post-318 tesserae may be restricted to Constantine’s five-year celebrations 320-321, 325-326, and 330-331.
Constantine issued imperial issues only, in the name of himself and other members of the imperial houses.
Early issues were produced in three sizes compatible with the regular coinage. All were struck in bronze, not brass.
All tesserae were produced at the imperial mint of Rome, with dies cut by the regular die-cutters.
These tesserae were part of Constantine’s official propaganda.
They were issued for the 5 March Festival of Isis, but the written messages propagate the emperor Constantine and his family.
They were not an attempt by pagans in Rome to promote traditional religion.
Constantine re-introduced Festival of Isis tesserae for New Year 313 immediately after defeating Maxentius and taking Rome.
Constantine issued tesserae annually 313 – 318. Post-318 tesserae may be restricted to Constantine’s five-year celebrations 320-321, 325-326, and 330-331.
Constantine issued imperial issues only, in the name of himself and other members of the imperial houses.
Early issues were produced in three sizes compatible with the regular coinage. All were struck in bronze, not brass.
All tesserae were produced at the imperial mint of Rome, with dies cut by the regular die-cutters.
These tesserae were part of Constantine’s official propaganda.
They were issued for the 5 March Festival of Isis, but the written messages propagate the emperor Constantine and his family.
They were not an attempt by pagans in Rome to promote traditional religion.
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The year 326 AD was a turning point for western civilization. The Roman emperor Constantine celebrated 20 years since his accession to the throne. He travelled from Nicomedia to Rome, and gave out donatives in gold and silver along the... more
The year 326 AD was a turning point for western civilization. The Roman emperor Constantine celebrated 20 years since his accession to the throne. He travelled from Nicomedia to Rome, and gave out donatives in gold and silver along the route. The final celebrations were held in Rome. They ended in disaster. Constantine’s eldest son Crispus was put to death on his father’s orders. A newly discovered coin indicates that this happened soon after the arrival of the imperial family in Rome. Constantine’s wife Fausta also met the same fate. The visit led to confrontation between Constantine and the ruling classes of Rome. There were no donatives in gold given to the Roman nobility, and the mint was closed when Constantine left the city. Constantine turned his back on Rome, and his new city Constantinopolis became the center of the Roman empire.
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The decision of Constantine the Great to build Constantinopolis, a “new Rome”, on the site of Byzantion profoundly changed the course of history. It is no exaggeration to say that without Constantinopolis, western civilization would have... more
The decision of Constantine the Great to build Constantinopolis, a “new Rome”, on the site of Byzantion profoundly changed the course of history. It is no exaggeration to say that without Constantinopolis, western civilization would have taken a very different course. Constantine was well aware that his decision was of paramount importance. This is evident from the large number of special issues of coins and medallions thought to have been minted for the inauguration on 11 May 330 CE. There are several silver and bronze “denominations” that were unique for this occasion. Remarkably, the largest silver medallions mirror hellenistic tetradrachms. Many types are small and often anepigraphic, making dating and interpretation difficult. This event was coordinated with a complete replacement of the entire bronze coinage in the whole empire, with types celebrating Rome, Constantinopolis and the army replacing the existing types. No Roman could avoid to know about the new city and its status. Taken together, these changes in minting at a single occasion has no parallel in the entire Roman history. Historical sources may not be clear regarding Constantine’s motivation, but the coinage unequivocally shows that Constantine intended the new city Constantinopolis to be exactly what it did become: a parallel to Rome and a coming center of the Roman empire.
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Phylogenetically basal, Llandovery parts of the diverse variolaris plexus of encrinurine trilobites havebeen assigned to a grade group, Nucleurus.. Parsimony analysis of 24 exoskeletal characters for adequately known species of Nucleurus... more
Phylogenetically basal, Llandovery parts of the diverse variolaris plexus of encrinurine trilobites havebeen assigned to a grade group, Nucleurus.. Parsimony analysis of 24 exoskeletal characters for adequately known species of Nucleurus and allied post-Llandovery taxa provides a phylogenetic scheme for reclassifying the base of the variolaris plexus. NucleurusRamsköld,, 1986 is redefined with Aeronian-Telychian core and Rhuddanian-Aeronian stem groups (Nucleurus s.s.
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Page 1. SILURIAN ODONTOPLEURID TRILOBITES FROM GOTLAND by LARS RAMSKÖLD abstract. Trilobites of the family Odontopleuridae are described from the Silurian of Gotland, Sweden. Twelve species and subspecies ...
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Alcymene n. gen. comprises a monophyletic group of calymenids known from the Ludlow Series of Sweden and the British Isles. The sister species Alcymene alveus and A. lindstroemi n. gen. and spp. (Hemse Beds, Gotland, Sweden) are most... more
Alcymene n. gen. comprises a monophyletic group of calymenids known from the Ludlow Series of Sweden and the British Isles. The sister species Alcymene alveus and A. lindstroemi n. gen. and spp. (Hemse Beds, Gotland, Sweden) are most closely related to the type species A. neointermedia (Richter and Richter), which occurs in overlying and underlying strata at nearby localities. Structural modification of A. alveus and A. lindstroemi, especially the development of a greatly broadened and troughed librigenal border, can be interpreted as “snowshoe” adaptations for increased stability on an offshore mud substrate.
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Cindarella eucalla Chen et al. from the Early Cambrian Chengjiang fauna is the closest relative of Xandarella spectaculum Hou et al. Cindarella and Xandarella are united as Xandarellida, a further component of Cambrian arachnate... more
Cindarella eucalla Chen et al. from the Early Cambrian Chengjiang fauna is the closest relative of Xandarella spectaculum Hou et al. Cindarella and Xandarella are united as Xandarellida, a further component of Cambrian arachnate diversity. Diagnostic of Xandarellida are ventral eyes, a posterior extension of the head shield that covers anterior trunk segments, and multiple somites per tergite in the rear part of the trunk. Somites and tergites are decoupled throughout the trunk in Cindarella. The bilobate structure of the exopod in xandarellids is widespread throughout the Arachnata.
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Page 1. Historical Biology, 1991, Vol. 4, pp. 267-283 O 1991 Harwood Academic Publishers, GmbH Reprints available directly from the publisher Printed in the United Kingdom Photocopying permitted by license only TRILOBITE MONOPHYLY... more
Page 1. Historical Biology, 1991, Vol. 4, pp. 267-283 O 1991 Harwood Academic Publishers, GmbH Reprints available directly from the publisher Printed in the United Kingdom Photocopying permitted by license only TRILOBITE MONOPHYLY REVISITED ...
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A data matrix of 32 characters, with a total of 132 character states and 48 terminal taxa of phacopid trilobites, was analysed using parsimony. The 108 most parsimonious trees have a length of 301 steps and a consistency index of 0.29.... more
A data matrix of 32 characters, with a total of 132 character states and 48 terminal taxa of phacopid trilobites, was analysed using parsimony. The 108 most parsimonious trees have a length of 301 steps and a consistency index of 0.29. Two major clades were found, one including species referred to Acernaspis and one with species referred to Ananaspis, Paciphacops, Viaphacops, and Phacops. Most homoplasy occurs between the major clades of the trees, rather than within them. The major clades were also analysed separately, resulting in trees with significantly higher consistency indices. We redefine the following supraspecific taxa to make them monophyletic: Acernaspis, Ananaspis, and Paciphacops. In addition, Kainops, new genus, is described for a clade consisting of six taxa previously assigned to Ananaspis and Paciphacops. The evolutionary pattern resulting from our cladogram is compared with the approaches of Campbell and Eldredge, and it is argued that some of the assumptions made by these authors regarding the phylogeny of the group are not valid. The biogeography of the group was also analysed. It is found that phacopids from the Ludlow and older strata are distributed globally, with an emphasis, perhaps due to a large number of suitable localities, on Northern Europe. However, the lineage of phacopines leading up to Phacops is, with some slight exceptions, basically confined to the United States, being entirely absent in Northern Europe. The main phacopine lineage does not re‐establish itself geographically until the middle Devonian. Finally, we analysed the evidence for polymorphism in phacopid trilobites, and reject this hypothesis on the basis of stratigraphy and the present cladogram.
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Cladistic relationships of Trilobita, Naraoiidae (five ingroup taxa), Helmetiida (five ingroup taxa), Xandarellida, and the Cambrian arachnatesRetifacies, Sinoburius, Emeraldella, andSidneyiaare investigated based on 29 characters.... more
Cladistic relationships of Trilobita, Naraoiidae (five ingroup taxa), Helmetiida (five ingroup taxa), Xandarellida, and the Cambrian arachnatesRetifacies, Sinoburius, Emeraldella, andSidneyiaare investigated based on 29 characters. Documentation of appendage morphology and other ventral structures inSaperionfrom the Chengjiang fauna permits an appraisal of helmetiid relationships. A monophyletic Trilobita [=“Olenellida” (Emuellida + Eutrilobita)] is defined by numerous synapomorphies, including exoskeletal calcification and dorsal eyes with calcified lenses and circumocular sutures. Helmetiida is a robust clade, resolved as (Helmetiidae (Tegopeltidae (Saperiidae + Skioldiidae))). Naraoiid monophyly is well-supported, but neither a naraoiid-trilobite nor a naraoiid-Retifaciesclade are parsimonious, the latter grouping (“Nectopleura”) being explicitly paraphyletic. A sister group relationship between Xandarellida andSinoburiusis endorsed, although character support is novel compared to previous groupings of these taxa. The fourth postantennal limb pair in trilobites, naraoiids, and apparently helmetiids is based beneath the cephalothoracic articulation. Reweighted characters favor Trilobita and Helmetiida as closest relatives, with Petalopleura and then Naraoiidae as sister groups.
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The first Laurentian records ofPacificurusRamsköld, 1986 are provided byPacificus chilorhodusn. sp. (latest Llandovery?–early Wenlock, Mackenzie Mountains, Canada) andPacificurussp. A (early Ludlow, northern Maine). These closely related... more
The first Laurentian records ofPacificurusRamsköld, 1986 are provided byPacificus chilorhodusn. sp. (latest Llandovery?–early Wenlock, Mackenzie Mountains, Canada) andPacificurussp. A (early Ludlow, northern Maine). These closely related species represent an early divergence (minimally late Llandovery) from Australian/Asian congenerics.
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... Page 2. 308 Lars Ramskold LETHAIA 21 (1988) Fig. I. The known ontogenetic material of Aceinuspis. ... Measurements were made using a gradated ocular, with maximum error in the order of Page 4. 310 Lars Ramskold LETHAIA 21 (1988) 20.05... more
... Page 2. 308 Lars Ramskold LETHAIA 21 (1988) Fig. I. The known ontogenetic material of Aceinuspis. ... Measurements were made using a gradated ocular, with maximum error in the order of Page 4. 310 Lars Ramskold LETHAIA 21 (1988) 20.05 mm. ...
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For most of 200 years, the concept of Trilobita included only forms with a calcified exoskeleton. Walcott&amp;amp;amp;amp;amp;#x27;s (1912) discovery in the Middle Cambrian Burgess Shale of arthropods broadly similar to trilobites but... more
For most of 200 years, the concept of Trilobita included only forms with a calcified exoskeleton. Walcott&amp;amp;amp;amp;amp;#x27;s (1912) discovery in the Middle Cambrian Burgess Shale of arthropods broadly similar to trilobites but lacking a min-eralized exoskeleton led him to include ...
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ABSTRACTThe subfamily Koneprusiinae is revised as part of a larger study of the Odontopleuridae, and Laethoprusia gen. nov. is described. The type species L. salax sp. nov. is from the Wenlock of Gotland, Sweden, and the genus is known... more
ABSTRACTThe subfamily Koneprusiinae is revised as part of a larger study of the Odontopleuridae, and Laethoprusia gen. nov. is described. The type species L. salax sp. nov. is from the Wenlock of Gotland, Sweden, and the genus is known also from the Wenlock of the Montagne Noire in south France, and from the Lower Devonian of Australia. The type species is most unusual among trilobites in possessing large fenestrae perforating the exoskeleton on segmental boundaries from the cephalic posterior margin to within the pygidium. The fenestrae were probably covered with soft tissues. Their function is enigmatic. Laethoprusia gen. nov. is the sister taxon to Isoprusia and/or Koneprusia. These genera are revised, and a review of all species assigned to them is given. A cladistic analysis of the best known taxa of Laethoprusia, Isoprusia, and Koneprusia is presented. Laethoprusia is the most derived genus of the subfamily, although stratigraphically it is the earliest.
Research Interests: Zoology, Earth Sciences, Geology, Biology, Cladistics, and 4 moreDevonian, Trilobite, Genus, and Taxon
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Surgical management is intended to eliminate or block infection originating in the root canals. The root end is customarily sealed to prevent pathogenic products remaining in the root canal from reaching the periradicular tissues. The... more
Surgical management is intended to eliminate or block infection originating in the root canals. The root end is customarily sealed to prevent pathogenic products remaining in the root canal from reaching the periradicular tissues. The purpose of this study was to evaluate the microbiologic and radiographic outcomes of surgical treatment of periradicular pathosis associated with teeth with necrotic pulps. One tooth from each of 10 patients was root-end resected and root-end filled without prior root canal treatment. One year postoperatively, the outcomes were assessed radiographically and the root canals were sampled for bacteria. Radiographic examination showed complete or incomplete (scar tissue) healing in 5 teeth and uncertain healing in the other 5 teeth. Bacteriologic samples from the root canals were positive in 9 of the 10 cases. In teeth with necrotic pulps, treatment of periradicular pathosis by surgery and root-end filling may show radiographic evidence of satisfactory healing 1 year postoperatively. However, viable bacteria may persist in the canals, constituting a potential risk factor for recurrence of periradicular pathosis.
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... Soft-part anatomy suggests that the group has affinities with the Burgess Shale &amp;amp;#x27;lobopod&amp;amp;#x27; Aysheaia 9 . All these marine, Cambrian forms are here grouped with the extant, terrestrial velvet worms in... more
... Soft-part anatomy suggests that the group has affinities with the Burgess Shale &amp;amp;#x27;lobopod&amp;amp;#x27; Aysheaia 9 . All these marine, Cambrian forms are here grouped with the extant, terrestrial velvet worms in the phylum ... 28. Gould, SJ Wonderful Life, 1−347 (Norton, New York, 1989). 29. ...
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Thermal effects and antibacterial properties of an Nd: YAG laser were studied to establish clinically safe levels of energy to deliver into the root canal and to determine the energy level needed to sterilize infected root canals. The... more
Thermal effects and antibacterial properties of an Nd: YAG laser were studied to establish clinically safe levels of energy to deliver into the root canal and to determine the energy level needed to sterilize infected root canals. The results indicate that lasing cycles of 3 J− s for ...
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Trilobites of five families (Cheiruridae, Odontopleuridae, Encrinuridae, Phacopidae and Dalmanitidae) are described from the Silurian of Gotland. Fifty-five species (fourty-four named, of which twe ...
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THE first chordate recorded from the Early Cambrian is the ceph-alochordate Yunnanozoon lividum from the 525 million-year-old Chengjiang fauna. Chordate features of Yunnanozoon are a noto-chord and an expanded filter-feeding pharynx with... more
THE first chordate recorded from the Early Cambrian is the ceph-alochordate Yunnanozoon lividum from the 525 million-year-old Chengjiang fauna. Chordate features of Yunnanozoon are a noto-chord and an expanded filter-feeding pharynx with an endostyle. Segmented ...
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An onychophoran-like fossil animal,Paucipodia inermisgen. et sp. nov., is described from the Lower Cambrian Chengjiang lagerstatte in Yunnan, China. The animal was soft-bodied, and possessed six pairs of unjointed legs, each having two... more
An onychophoran-like fossil animal,Paucipodia inermisgen. et sp. nov., is described from the Lower Cambrian Chengjiang lagerstatte in Yunnan, China. The animal was soft-bodied, and possessed six pairs of unjointed legs, each having two claws distally. The body was finely annulated, lacked trunk plates, and apparently terminated posteriorly with the last leg pair, without preserved evidence of a posterior trunk extension.Paucipodiawidens the morphological range hitherto known in Cambrian lobopodians, notably regarding leg number and presence or absence of plates. Its morphology also provides support for the recently suggested anteroposterior orientation ofHallucigeniaandMicrodictyon.
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Fortey's and Whittington's recent refutation of Lauterbach's hypothesis of a paraphyletic Trilobita is supported However, much of the character evidence raised by Fortey and Whittington to substantiate the monophyly of the... more
Fortey's and Whittington's recent refutation of Lauterbach's hypothesis of a paraphyletic Trilobita is supported However, much of the character evidence raised by Fortey and Whittington to substantiate the monophyly of the Trilobita (including, inter alia, "Olenellinae " and Agnostoidea) is ambiguous Of seven proposed synapomorphies only one (dorsal cuticle calcification) may be maintained at that node after testing within a cladistic framework The other six characters are either constrained by calcification or define nodes up or down the cladogram As positioned by Fortey's and Whittington's characters, Agnostoidea could be regarded either as the most primitive trilobites, or as being outside that clade. Lauterbach's support for an "olenelline"-chelicerate clade is found to include interdependent characters which are reduced here to two testable derived similarities Only one of these may conform to general criteria indicative of homo...
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Phylogenetically basal, Llandovery parts of the diverse variolaris plexus of encrinurine trilobites havebeen assigned to a grade group, Nucleurus.. Parsimony analysis of 24 exoskeletal characters for adequately known species of Nucleurus... more
Phylogenetically basal, Llandovery parts of the diverse variolaris plexus of encrinurine trilobites havebeen assigned to a grade group, Nucleurus.. Parsimony analysis of 24 exoskeletal characters for adequately known species of Nucleurus and allied post-Llandovery taxa provides a phylogenetic scheme for reclassifying the base of the variolaris plexus. NucleurusRamsköld,, 1986 is redefined with Aeronian-Telychian core and Rhuddanian-Aeronian stem groups (Nucleurus s.s.
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Silurian (Llandovery-Ludlow) Encrinurinae from Wisconsin, Indiana, and Illinois include species of Balizoma Holloway, 1980, Curiella Lamont, 1978, Distyrax Lane, 1988, Encrinurus Emmrich, 1844, Mackenziurus Edgecombe and Chatterton,... more
Silurian (Llandovery-Ludlow) Encrinurinae from Wisconsin, Indiana, and Illinois include species of Balizoma Holloway, 1980, Curiella Lamont, 1978, Distyrax Lane, 1988, Encrinurus Emmrich, 1844, Mackenziurus Edgecombe and Chatterton, 1990a, and Nucleurus Ramsköld, 1986. Mackenziurus lauriae n. sp. is described from Wenlock strata of the Racine and Sugar Run Dolomites; nine segments in the holaspid thorax are the fewest known for any encrinurid. A square rostral plate is diagnostic of Mackenziurus. New morphological data are provided by Illinois specimens of Balizoma indianensis (Kindle and Breger, 1904) from the Wenlock-Ludlow Racine Dolomite, and of Curiella tuberculifrons (Weller, 1907) from the Llandovery Elwood-Wilhelmi Formations. Nucleurus n. sp. is possibly from Llandovery strata of Wisconsin. Distyrax n. sp. occurs in the Brandon Bridge Member (late Llandovery-early Wenlock) of the Joliet Dolomite in Illinois. The type pygidia and possible topotype material of Encrinurus nereus Hall, 1867, confirm assignment to that genus as currently viewed; this reefal species is distinct from the closely related inter-reef species E. egani Miller, 1880, and appears to be distinct from reefal E. reflexus Raymond, 1916. Lectotypes are selected for those Encrinurus species.