Brachiopoda

A new exceptionally preserved marginal marine biota is reported from the Late Ordovician Big Hill Formation of Stonington Peninsula in Michigan's Upper Peninsula. The new Lagerstätte hosts a moderately diverse fauna of medusae, linguloid brachiopods, non-mineralized arthropods and orthocone nautiloids, alongside dasycladalean green algae. The biota is similar to those of Lagerstätten from the Late Ordovician of Canada, revealing an extensive distribution of a distinctive marginal marine palaeocommunity in Laurentia at this time. The Big Hill biota extends the geographical range of exceptionally preserved Late Ordovician faunas in Laurentia and indicates that further examples remain to be discovered.

Brachiopods are a lineage of invertebrates well known for the breadth and depth of their fossil record. Although the quality of
this fossil record attracts the attention of paleontologists, geochemists, and paleoclimatologists, modern day brachiopods are
also of interest to evolutionary biologists due to their potential to address a variety of questions ranging from developmental
biology to biomineralization. The brachiopod shell is a composite material primarily composed of either calcite or calcium
phosphate in close association with proteins and polysaccharides which give these composite structures their material properties. The information content of these biomolecules, sequestered within the shell during its construction, has the potential to
inform hypotheses focused on describing how brachiopod shell formation evolved. Here, using high throughput proteomic
approaches and next generation sequencing, we have surveyed and characterized the first shell-proteome and shell-forming
transcriptome of any brachiopod, the South American Magellania venosa (Rhynchonelliformea: Terebratulida). We find that the
seven most abundant proteins present in the shell are unique to M. venosa, but that these proteins display biochemical features
found in other metazoan biomineralization proteins. We can also detect some M. venosa proteins that display significant
sequence similarity to other metazoan biomineralization proteins, suggesting that some elements of the brachiopod shellforming proteome are deeply evolutionarily conserved. We also employed a variety of preparation methods to isolate shell
proteins and find that in comparison to the shells of other spiralian invertebrates (such as mollusks) the shell ultrastructure of
M. venosa may explain the effects these preparation strategies have on our results.

May, A. (1996a): Relationship among sea-level fluctuation, biogeography, and bioevents of the Devonian: an attempt to approach a powerful, but simple model for complex long-range control of biotic crises. - Geolines, 3: 38-49, 2 figs.; Praha.

ABSTRACT. Connections among changing sea-level, development of marine biogeography and appearance of bioevents in Devonian times are emphasised. Decreasing Devonian provincialism of the marine fauna reflects rising sea-level of global ocean. Whereas the Emsian sea-level lowstand was accompanied by strong provincialism of the marine communities, the Frasnian highstands were linked to an unusual decrease of provincialism. As generally documented, the partial but intensive transgressional events (often related to bioevents) were usually associated with a decrease of the provincialism. The best explanation for the majority of Devonian bioevents is the effect of oceanic anoxia. A model suggested herein operates with a fast transgression related to fast ocean sea-level rise. A direct consequence of this fast transgression was the increased primary biomass production (caused by both increased infiux of nutrients and increased total surface of shallow seas). Decreased oxygen supply of oceans continued this process being caused by the global temperature increase which resulted from the albedo decrease. These consequences of these combined factors produced an oceanic anoxic event which started the extinction processes of the bioevent. The well-documented pattern of intensified biological crises during the Devonian, time-slice by time-slice (from Emsian to Frasnian), is explained as a direct result of decreased provincialism of the marine fauna. Both decrease of the provincialism and increased intensity of the Devonian bioevents can be deduced directly or indirectly from changes of global sea-level. This simply constructed but very complex explanation yields two advantages: first, it needs only very few infiuencing factors, second, it can basically renounce incalculable influences (e.g. meteorite impacts). The suggested concept of oceanic anoxic events can explain also other major bioevents of the Earth history.

KURZFASSUNG: Der Artikel versucht, Zusammenhänge zwischen den Veränderungen des Meeresspiegels, der Entwicklung der marinen Biogeographie und den Bioevents im Devon herauszuarbeiten und zu erklären. Die Entwicklung des Faunen-Provinzialismus im Devon ist ein Ergebnis der Entwicklung des globalen Meeresspiegels. Im Emsium war der Meeresspiegel niedrig und der Provinzialismus der Meeresfauna gross, im Frasnium war der Meeresspiegel hoch und der Provinzialismus sehr gering. Insbesondere einige Trangressions-Schübe, die sich auch als Bioevents bemerkbar machten, führten zu schnellen Abnahmen der Grösse des Provinzialismus. Die beste Erklärung für die meisten devonischen Bioevents ist das Auftreten von ozeanischen anoxischen Events. Das hier vorgestellte Modell setzt bei schnellen Transgressionen an, die durch schnelle Meeresspiegel-Anstiege verursacht wurden. Die Konsequenzen einer schnellen Transgression waren gesteigerte Primär produktion organischer Substanz und geringere Sauerstoff- Versorgung der Ozeane, was zusammen zum ozeanischen anoxischen Event und zum Bioevent führte. Der Umstand, dass die Intensität der Bioevents vom Emsium zum Frasnium zunahm, wird durch die Abnahme des Provinzialismus der Meeresfauna in dieser Zeit erklärt. Sowohl die Entwicklung des Provinzialismus der marinen Fauna als auch das Auftreten und die Intensität der Bioevents im Devon lassen sich direkt oder mittelbar aus der Entwicklung des globalen Meeresspiegels ableiten. Dieser sehr umfassende Erklärungsansatz hat den Vorteil, mit sehr wenigen Einfiussfaktoren auszukommen und auf unkalkulierbare Einwirkungen (wie z.B. Meteoriten-Einschläge) völlig verzichten zu können. Vermutlich ist das hier entwickelte Konzept eines ozeanischen anoxischen Events auch auf andere Bioevents übertragbar.

KEYWORDS: Devonian, Kellwasser Event, ecosystems, biogeography, sea level fiuctuation.

Preliminary review of taxonomy of the brachiopod order AĘpida and its stratigraphic distribution in the late Frasnian Kellwasser Crisis of several regions of Laurussia, westem Siberia and South China point to their moderate diversity and stepdown but irregular extinction pattern. The distinctive character of the late Frasnian atrypid fauna is emphasised by several relict genera, marked by recurrent and possibly aberrant characters (mainly in ornamentation types), tendency to size reduction and homeomorphy in some taxa. The transgressive/hypoxic Lower Kellwasser Event and preceding eustatic changes during the Palmatolepis rhenanaZone had only a regional destructive effect, and were linked rather to an enhanced dispersal of the last generic set of aĘpids. The VariaĘpinae, Spinatrypinae and Iowatryp,a-group seem to belong to the latest surviving atrypids. The final demise of the remaining atrypids (and some other articulate brachiopods, e.g., gypidulids) coincided with the fransgressiv...

On Aferdou El Mrakib, a large reef mound in
the Maı¨der region (Anti-Atlas, Morocco), thick-shelled
gypidulids of two genera are locally very abundant. Like
Stringocephalus in the shallow water limestone formations
in Germany, these Moroccan brachiopods of the genera
Devonogypa and Ivdelinia often display greenish shells. By
analysing these shells by EDX, it turned out that the colour
was possibly caused by impurities of Fe2?-ions. The concentration
varies, indicating that the colour is less dependent
on the concentration than on shell thickness, because only the
thickest parts of the shells appear green and thin-shelled
forms never display the green colour. There is also some
indication that the Fe content increases towards deeper shell
layers (further away from the surface). In addition, we
examined the quality and spatial distribution of sublethal
injuries in over 200 specimens of Devonogypa and Ivdelinia.
Shape, spatial distribution on the shells, and abundance of
the sublethal injuries support the hypotheses that (1) the
injuries had several causes, (2) some of these were inflicted
by predators, probably cephalopods, and (3) many fractures
and deformations might have been caused by the brachiopod
shells hitting each other in dense populations in agitated
water. The existence of dense clusters, built by the association
of members of both genera or of only one taxon, is
corroborated by the patchy occurrence of these brachiopods.

The collection and study of benthic fauna from Middle Devonian carbonate buildups of the Maider Basin in the eastern Anti-Atlas of Morocco permitted the taxonomic revision of previously described brachiopods from this area. Rhynchonellids dominate the brachiopod fauna. In this work, however, the focus is put on the description of a new gypidulid species, Ivdelinia pulchra, which belongs to the family Gypidulidae (subfamily Ivdelininae), found among the brachiopods from the Aferdou el Mrakib reef mound. It represents the youngest Ivdelinia species so far described and is compared with other ivdelinids. Ivdelinia pulchra occurs as densely packed communities which lived in a carbonate predominant environment during the earlier stage of reef mound growth, suggesting a more or less allochthonous state of these communities. However, this taxon does not properly belong to the reef guild. In addition we discuss the palaeoecology of the new species.

S’estudia la presència d’Oichnus simplex Bromley, 1981 en una omunitat de braquiòpodes de l’Aptià inferior de Vallibona (conca del Maestrat). S’ha constatat la presència sobre Burrirhynchia miliani (Calzada, 1971) i Loriolithyris solei (Calzada, 1976). La freqüència de depredació és baixa (2,2% i 6,8%). És possible que el depredador perforador fora un gasteròpode. Aquestes són les primeres dades publicades d’Oichnus simplex sobre braquiòpodes al Cretaci Inferior a la península Ibèrica i per a tot el registre fòssil de la conca del Maestrat.
Abstract
Presence of Oichnus simplex on brachiopods of the lower Aptian of Vallibona (Maestrat basin). The presence of Oichnus simplex Bromley, 1981, is studied on a community of brachiopods of the lower Aptiá of Vallibona (Maestrat basin). The presence was found on Burrirhynchia miliani (Calzada, 1971) and Loriolithyris solei (Calzada, 1976). The predation frequency is low (2.2% and 6.8%). It is possible that the drilling predator was a gastropod. These are the first published data of Oichnus simplex on brachiopods in the Lower Cretaceous of the Iberian  Península and for the entire fossil record of the Maestrat basin.

Preliminary review of taxonomy of the brachiopod order AĘpida and its stratigraphic distribution in the late Frasnian Kellwasser Crisis of several regions of Laurussia, westem Siberia and South China point to their moderate diversity and stepdown but irregular extinction pattern. The distinctive character of the late Frasnian atrypid fauna is empha-sised by several relict genera, marked by recurrent and possibly aberrant characters (mainly in ornamentation types), tendency to size reduction and homeomorphy in some taxa. The transgressive/hypoxic Lower Kellwasser Event and preceding eustatic changes during the Palmatolepis rhenanaZone had only a regional destructive effect, and were linked rathęr to an enhanced dispersal of the last generic set of aĘpids. The VariaĘpi-nae, Spinatrypinae and Iowatryp,a-group seem to belong to the latest surviving atrypids. The final demise of the remaining atrypids (and some other articulate brachiopods, e.g., gypidulids) coincided with the fransgress...

The interpretation of pedicle soft tissue preservation in a unique brachiopod specimen of Wenlock (Silurian) age from Herefordshire, western England, is reassessed. Bethia serraticulma, assigned originally to the Orthida, is more probably a member of the Strophomenida (Plectambonitoidea). The supposed pedicle structure is more plausibly a weakly mineralised pedicle sheath, which is a common morphological and functional development in the early ontogeny of a number of Palaeozoic brachiopod lineages.

May, A. (1991b): Die Fossilführung des westsauerländischen Givetiums (Devon, Rheinisches Schiefergebirge) in der Sammlung des Städtischen Museums Menden. - Geologie und Paläontologie in Westfalen, 17: 7-42, 20 figs.; Münster.

[The fossil-contents of the Givetian in the Western Sauerland (Devonian, Rhenish Schiefergebirge) shown by the collections of the Municipal Museum Menden (F.R. Germany)].  Abstract: The Municipal Museum Menden/Sauerland possesses extensive fossil collections from the northwestern Sauerland and its neighbourhood out of the Givetian strata Oberhonsel-Formation, Massenkalk, and Flinz. This collection was built 1912-1939 in cooperation with K. TORLEY. Brachiopods and reef builders (corals and stromatoporoids) are the most important fossil groups. The re-examination of the collection gave some new (bio-) stratigraphical informations (Fig. 2). The upper part of the Oberhonsel-Formation is as old as the Dreimühlen-Formation in the Eifel. Following species are described for the first time fram the Eastern Rhenish Schiefergebirge: the tabulate coral Aulopora lata LECOMPTE 1939, the rugose coral Siphonophrentis cantabrica BIRENHEIDE 1978, and the brachiopods Spinatrypa orthoclina COPPER 1967, Spinatrypina girzenensis COPPER 1967, and Desquamatia (Variatrypa) ajugata COPPER 1965. The anarcestid cephalopod Sobolewia amplorotundata (Torley 1908) is figured for the first time. Other Givetian fossils are as well figured.

Key words: Brachiopoda, Anthozoa, Cephalopoda, Devonian, Givetian, faunal list, biostratigraphy, Rhenish Schiefergebirge, Sauerland, museum.
Schlüsselwörter: Brachiopoda, Anthozoa, Cephalopoda, Devon, Givetium, Fauna, Biostratigraphie, Rheinisches Schiefergebirge, Sauerland, Museum.

Zusammenfassung: Das Städtische Museum Menden besitzt umfangreiche Fossilaufsammlungen aus dem Nordwest-Sauerland und angrenzenden Gebieten, die aus der Oberhonsel-Formation, dem Massenkalk und dem Flinz des Givetiums stammen. In dieser 1912-1939 unter Mitwirkung von K. TORLEY entstandenen Sammlung dominieren Brachiopoden und Riffbildner. Der obere Teil der Oberhonsel-Formation entspricht zeitlich der Dreimühlen- Formation der Eifel. Aus dem Rechtsrheinischen Schiefergebirge werden erstmalig beschrieben: die tabulate Koralle Aulopora lata LECOMPTE 1939, die rugose Koralle Siphonophrentis cantabrica BIRENHEIDE 1978 und die Brachiopoden Spinatrypa orthoclina COPPER 1967, Spinatrypina girzenensis COPPER 1967 und Desquamatia (Variatrypa) ajugata COPPER 1965. Der Anarcestide Sobolewia amplorotundata (TORLEY 1908) wird erstmalig abgebildet.