The vertebrate recovery after the end-Permian mass extinction can be approached through the ichno... more The vertebrate recovery after the end-Permian mass extinction can be approached through the ichnological record, which is much more abundant than body fossils. The late Olenekian (Early Triassic) tetrapod ichnoassemblage of the Catalan Pyrenean Basin is the most complete and diverse of this age from Western Tethys. This extensional basin, composed of several depocenters, was formed in the latest phases of the Variscan orogeny (Pangea breakup) and was infilled by braided and meandering fluvial systems of the red-beds Bunt-sandstein facies. Abundant and diverse tetrapod ichnites are recorded in these facies, including Prorotodactylus mesaxonichnus isp. nov. (tracks possibly produced by euparker-iids), cf. Rotodactylus, at least two large chirotheriid morphotypes (archosauriform track-makers), Rhynchosauroides cf. schochardti, two other undetermined Rhynchosauroides forms, an undetermined Morphotype A (archosauromorph trackmakers) and two types of Characichnos isp. (swimming traces, here associated to archosauromorph trackmakers). The Pyrenean ichnoassemblage suggests a relatively homogeneous ichnofaunal composition through the late Early Triassic of Central Pangea, characterized by the presence of Pro-rotodactylus and Rotodactylus. Small archosauromorph tracks dominate and present a wide distribution through the different fluviatile facies of the Triassic Pyrenean Basin, with large archosaurian footprints being present in a lesser degree. Archosauromorphs radiated and diversified through the Triassic vertebrate recovery, which ultimately lead to the archo-saur and dinosaur dominance of the Mesozoic.
Maastrichtian biodiversity of medium- and large-sized terrestrial vertebrates is well known in Eu... more Maastrichtian biodiversity of medium- and large-sized terrestrial vertebrates is well known in Europe and, specifically, in the Iberian Peninsula. Regarding small-sized herpetofaunas (lissamphibians and squamates), only a few European sites have yielded a significant amount of fossils, and they are still poorly known from the Iberian Peninsula. Recent fieldwork carried out at several sites exposing the Tremp Formation (Southern Pyrenees) has revealed four new localities yielding microvertebrates. Two of them (L'Espinau and Serrat del Rostiar-1) are relatively diverse in herpetofauna, containing albanerpe-tontids, four different anurans (two different alytids, a pelobatid or gobiatid and a palaeobatrachid), as well as six types of squamates (including scincomorphs, iguanids, anguids and probably gekkotans). Most of these groups are shared with other Campanian-Maastrichtian localities from eastern Iberia although, in some cases, morphological differences might suggest the presence of new lower-level taxa (i.e., genera or species). Also remarkable is the presence of alytines and likely gekkotans that would represent the oldest records of these taxa in Europe and in the Iberian Peninsula, respectively. Taxa of Laurasian origin are common at the Serrat del Rostiar-1 and L'Espinau localities, while Gondwanan taxa are lacking in all cases. Evidence for Asian immigrants (i.e., alytines) is found amongst anurans. Some differences regarding the faunal composition could be explained by environmental factors (i.e., coastal wetlands vs. fluvial settings), although the possibility of taphonomic biases cannot be ruled out.
The continental Permian–Triassic transition in southern Europe presents little paleontological ev... more The continental Permian–Triassic transition in southern Europe presents little paleontological evidence of the Permian mass extinction and the subsequent faunal recovery during the early stages of the Triassic. New strati- graphic, sedimentological and paleontological analyses from Middle–Upper Permian to Lower–Middle Triassic deposits of the Catalan Pyrenees (NE Iberian Peninsula) allow to better constrain the Permian–Triassic succession in the Western Tethys basins, and provide new (bio-) chronologic data. For the first time, a large vertebra attrib- uted to a caseid synapsid from the ?Middle Permian is reported from the Iberian Peninsula—one of the few report- ed from western Europe. Osteological and ichnological records from the Triassic Buntsandstein facies reveal a great tetrapod ichnodiversity, dominated by small to medium archosauromorphs and lepidosauromorphs (Rhynchosauroides cf. schochardti, R. isp. 1 and 2, Prorotodactylus–Rotodactylus), an undetermined Morphotype A and to a lesser degree large archosaurians (chirotheriids), overall suggesting a late Early Triassic–early Middle Triassic age. This is in agreement with recent palynological analyses in the Buntsandstein basal beds that identify different lycopod spores and other bisaccate and taeniate pollen types of late Olenekian age (Early Triassic). The Permian caseid vertebra was found in a playa-lake setting with a low influence of fluvial water channels and re- lated to the distal parts of alluvial fans. In contrast, the Triassic Buntsandstein facies correspond to complex alluvial fan systems, dominated by high-energy channels and crevasse splay deposits, hence a faunal and environmental turnover is observed. The Pyrenean biostratigraphical data show similarities with those of the nearby Western Te- thys basins, and can be tentatively correlated with North African and European basins. The Triassic Pyrenean fossil remains might rank among the oldest continental records of the Western Tethys, providing new keys to decipher the Triassic faunal biogeography and recovery.
The continental Permian-Triassic transition in southern Europe presents little paleontological ev... more The continental Permian-Triassic transition in southern Europe presents little paleontological evidence of the Permian mass extinction and the subsequent faunal recovery during the early stages of the Triassic. New stratigraphic, sedimentological and paleontological analyses from Middle-Upper Permian to Lower-Middle Triassic deposits of the Catalan Pyrenees (NE Iberian Peninsula) allow to better constrain the Permian-Triassic succession in the Western Tethys basins, and provide new (bio-) chronologic data. For the first time, a large vertebra attributed to a caseid synapsid from the ?Middle Permian is reported from the Iberian Peninsula - one of the few reported from western Europe. Osteological and ichnological records from the Triassic Buntsandstein facies reveal a great tetrapod ichnodiversity, dominated by small to medium archosauromorphs and lepidosauromorphs (Rhynchosauroides cf. schochardti, R. isp. 1 and 2, Prorotodactylus-Rotodactylus, an undetermined Morphotype A and to a lesser degree large archosaurians (chirotheriids), overall suggesting a late Early Triassic-early Middle Triassic age. This is in agreement with recent palynological analyses in the Buntsandstein basal beds that identify different lycopod spores and other bisaccate and taeniate pollen types of late Olenekian age (Early Triassic). The Permian caseid vertebra was found in a playa-lake setting with a low influence of fluvial water channels and related to the distal parts of alluvial fans. In contrast, the Triassic Buntsandstein facies correspond to complex alluvial fan systems, dominated by highenergy channels and crevasse splay deposits, hence a faunal and environmental turnover is observed. The Pyrenean biostratigraphical data show similarities with those of the nearby Western Tethys basins, and can be tentatively correlated with North African and European basins. The Triassic Pyrenean fossil remains might rank among the continental oldest records of the Western Tethys, providing new keys to decipher the Triassic faunal biogeography and recovery.
A new Triassic actinopterygian specimen including the skull and the anterior portion of the squam... more A new Triassic actinopterygian specimen including the skull and the anterior portion of the squamation is described. The specimen represents the first find of a colobodontid from the Muschelkalk of Odèn locality (Pyrenean Basin, NE Iberian Peninsula). Although fragmentarily preserved in part and counterpart, the specimen shows considerable morphological details and fine preservation of bone structure. Comparisons to several well-known species of Colobodus AgAssiz, 1844 and Crenilepis Dames, 1888 from the Middle Triassic of the Besano Formation (northern Italy and southern Switzerland) and two specimens from Alcover outcrops (Catalonian Basin, NE Iberian Peninsula) previously assigned to Perleidus giganteus Beltan, 1972 enables a taxonomical re-assessment of Iberian colobodontids. The three specimens from the Iberian Peninsula are transferred to the genus Colobodus and re-named as Colobodus giganteus (Beltan, 1972) comb. nov. This taxon is the largest within the genus Colobodus and it is characterized by three diagnostic features: the series of supraorbitals, with more numerous and small ossifications in comparison with the rest of Colobodus species; the branchiostegal rays, more slender than in C. bassanii; and the teeth on the jaw margins not as well developed as in all other species of Colobodus, despite its considerable size.
The Upper Cretaceous outcrops of Armuña (Segovia Province, Spain) yielded relatively abundant mat... more The Upper Cretaceous outcrops of Armuña (Segovia Province, Spain) yielded relatively abundant material of vertebrates during prospection and excavation in the second half of the 1980s. However, little has been published on these remains. A new analysis of the specimens from this upper Campanian site reveals the presence of some clades in the site for the first time (e.g., Dortokidae, Anguimorpha, Mosasauroidea). Furthermore, the material of the clades previously recognized there has been reviewed and described in more detail, with some previous systematic attributions confirmed and others refuted. Consequently, a relatively high local diversity has been identified. New taxa (i.e., a member of Anguimorpha and a eusuchian crocodyliform) are identified in Armuña, coexisting with other taxa previously described in other sites from the Iberoarmorican Realm. The vertebrates from Armuña confirm that the fauna from the Upper Cretaceous of the Iberian Peninsula is composed of a mixture of European endemic clades and lineages shared with other continents such as North America (e.g., anguimorphs) and Africa (e.g., bothremydids).
Cadurcogekko rugosus Augé, 2005 was described as a gekkotan lizard from the Eocene of France. A r... more Cadurcogekko rugosus Augé, 2005 was described as a gekkotan lizard from the Eocene of France. A revision of the material has revealed that the holotype, a nearly complete dentary, actually belongs to a scincid lizard, for which we erect the new genus Gekkomimus. The rest of material originally referred to C. rugosus is of undoubted gekkotan nature and is included in the new species Cadurcogekko verus, with the exception of a partial left dentary belonging to the iguanid lizard Cadurciguana hoffstetteri.
Cranial and postcranial remains from the Middle Triassic of the Northeastern part of the Iberian ... more Cranial and postcranial remains from the Middle Triassic of the Northeastern part of the Iberian Peninsula are reported and tentatively assigned to Procolophonidae. The finding is the first occurrence of a procolophonid parareptile in the Iberian Peninsula, representing the southernmost record of the group in Europe. The fossilbearing locality is dated as Anisian (Middle Triassic) and includes three tooth-bearing bones, two cranial bone fragments and one interclavicle. The mandible described herein includes nine teeth. No cusps or complete crowns are preserved, but sections of the teeth are available. The three anterior teeth progressively decrease in size from front to back, whereas the teeth from the fourth to the eighth position present the opposite trend. The last tooth (the ninth) is clearly reduced in comparison to the previous ones. A close relationship with Anomoiodon-Kapes is suggested, however, more material is required in order to assess the exact taxonomical determination of the Iberian remains. This finding is expected to shed some light on the geographical distribution of procolophonines.
The evolution of blanid amphisbaenians (Mediterranean worm lizards) is mainly inferred based on m... more The evolution of blanid amphisbaenians (Mediterranean worm lizards) is mainly inferred based on molecular studies, despite their fossils are common in Cenozoic European localities. This is because the fossil record exclusively consists in isolated elements of limited taxonomic value. We describe the only known fossil amphisbaenian skull from Europe – attributed to Blanus mendezi sp. nov. (Amphisbaenia, Blanidae) – which represents the most informative fossil blanid material ever described. This specimen, from the Middle Miocene of Abocador de Can Mata (11.6 Ma, MN7+8) in the Vallès- Penedès Basin (Catalonia, NE Iberian Peninsula), unambiguously asserts the presence of Blanus in the Miocene of Europe. This reinforces the referral to this genus of the previously-known, much more incomplete and poorly-diagnostic material from other localities of the European Neogene. Our analysis – integrating the available molecular, paleontological and biogeographic data – suggests that the new species postdates the divergence between the two main (Eastern and Western Mediterranean) extant clades of blanids, and probably precedes the split between the Iberian and North-Western African subclades. This supports previous paleobiogeographic scenarios for blanid evolution and provides a significant minimum divergence time for calibrating molecular analyses of blanid phylogeny.
Recent finds of tetrapod ichnites in the red-bed and volcaniclastic succession of the Iberian Pyr... more Recent finds of tetrapod ichnites in the red-bed and volcaniclastic succession of the Iberian Pyrenean Basin permits an assessment of the faunal diversity and palaeoenvironment of a late early Permian setting. The tetrapod ichnoassemblage is inferred with the aid of photogrammetry and constituted by Batrachichnus salamandroides, Limnopus isp., cf. Amphisauropus (these three ichnotaxa present associated swimming traces, assigned to Characichnos), cf. Ichniotherium, Dromopus isp., cf. Varanopus, Hyloidichnus isp. and Dimetropus leisnerianus. These ichnotaxa suggest the presence of temnospondyls, seymouriamorphs, diadectomorphs, araeoscelids, captorhinids and synapsid pelycosaurs as potential trackmakers. These faunas correlate to the late early Permian. Two ichnoassociations correspond to two different palaeoenvironments that were permanently or occasionally aquatic (meandering fluvial systems and unconfined runoff surfaces, respectively). Ichnotaxa in the fluvial system is more diverse and abundant than in the runoff surfaces system. The Iberian Pyrenean ichnoassemblage reveals the faunistic connection and similarities among nearing basins (Spain, southern France and Morocco) differing from the Central European basins (i.e. German Tambach Formation). Based on the palaeogeography and the climate models of the early Permian, we suggest the correlation of ichnofaunal composition with different palaeoclimate biomes. This results in a diffuse boundary of Gondwana–Laurasia land masses, indicating no geographic barriers but a possible climate control on the faunal distribution. Further studies, integrating data from distant tracksites, should refine these biome boundaries.
The vertebrate recovery after the end-Permian mass extinction can be approached through the ichno... more The vertebrate recovery after the end-Permian mass extinction can be approached through the ichnological record, which is much more abundant than body fossils. The late Olenekian (Early Triassic) tetrapod ichnoassemblage of the Catalan Pyrenean Basin is the most complete and diverse of this age from Western Tethys. This extensional basin, composed of several depocenters, was formed in the latest phases of the Variscan orogeny (Pangea breakup) and was infilled by braided and meandering fluvial systems of the red-beds Bunt-sandstein facies. Abundant and diverse tetrapod ichnites are recorded in these facies, including Prorotodactylus mesaxonichnus isp. nov. (tracks possibly produced by euparker-iids), cf. Rotodactylus, at least two large chirotheriid morphotypes (archosauriform track-makers), Rhynchosauroides cf. schochardti, two other undetermined Rhynchosauroides forms, an undetermined Morphotype A (archosauromorph trackmakers) and two types of Characichnos isp. (swimming traces, here associated to archosauromorph trackmakers). The Pyrenean ichnoassemblage suggests a relatively homogeneous ichnofaunal composition through the late Early Triassic of Central Pangea, characterized by the presence of Pro-rotodactylus and Rotodactylus. Small archosauromorph tracks dominate and present a wide distribution through the different fluviatile facies of the Triassic Pyrenean Basin, with large archosaurian footprints being present in a lesser degree. Archosauromorphs radiated and diversified through the Triassic vertebrate recovery, which ultimately lead to the archo-saur and dinosaur dominance of the Mesozoic.
Maastrichtian biodiversity of medium- and large-sized terrestrial vertebrates is well known in Eu... more Maastrichtian biodiversity of medium- and large-sized terrestrial vertebrates is well known in Europe and, specifically, in the Iberian Peninsula. Regarding small-sized herpetofaunas (lissamphibians and squamates), only a few European sites have yielded a significant amount of fossils, and they are still poorly known from the Iberian Peninsula. Recent fieldwork carried out at several sites exposing the Tremp Formation (Southern Pyrenees) has revealed four new localities yielding microvertebrates. Two of them (L'Espinau and Serrat del Rostiar-1) are relatively diverse in herpetofauna, containing albanerpe-tontids, four different anurans (two different alytids, a pelobatid or gobiatid and a palaeobatrachid), as well as six types of squamates (including scincomorphs, iguanids, anguids and probably gekkotans). Most of these groups are shared with other Campanian-Maastrichtian localities from eastern Iberia although, in some cases, morphological differences might suggest the presence of new lower-level taxa (i.e., genera or species). Also remarkable is the presence of alytines and likely gekkotans that would represent the oldest records of these taxa in Europe and in the Iberian Peninsula, respectively. Taxa of Laurasian origin are common at the Serrat del Rostiar-1 and L'Espinau localities, while Gondwanan taxa are lacking in all cases. Evidence for Asian immigrants (i.e., alytines) is found amongst anurans. Some differences regarding the faunal composition could be explained by environmental factors (i.e., coastal wetlands vs. fluvial settings), although the possibility of taphonomic biases cannot be ruled out.
The continental Permian–Triassic transition in southern Europe presents little paleontological ev... more The continental Permian–Triassic transition in southern Europe presents little paleontological evidence of the Permian mass extinction and the subsequent faunal recovery during the early stages of the Triassic. New strati- graphic, sedimentological and paleontological analyses from Middle–Upper Permian to Lower–Middle Triassic deposits of the Catalan Pyrenees (NE Iberian Peninsula) allow to better constrain the Permian–Triassic succession in the Western Tethys basins, and provide new (bio-) chronologic data. For the first time, a large vertebra attrib- uted to a caseid synapsid from the ?Middle Permian is reported from the Iberian Peninsula—one of the few report- ed from western Europe. Osteological and ichnological records from the Triassic Buntsandstein facies reveal a great tetrapod ichnodiversity, dominated by small to medium archosauromorphs and lepidosauromorphs (Rhynchosauroides cf. schochardti, R. isp. 1 and 2, Prorotodactylus–Rotodactylus), an undetermined Morphotype A and to a lesser degree large archosaurians (chirotheriids), overall suggesting a late Early Triassic–early Middle Triassic age. This is in agreement with recent palynological analyses in the Buntsandstein basal beds that identify different lycopod spores and other bisaccate and taeniate pollen types of late Olenekian age (Early Triassic). The Permian caseid vertebra was found in a playa-lake setting with a low influence of fluvial water channels and re- lated to the distal parts of alluvial fans. In contrast, the Triassic Buntsandstein facies correspond to complex alluvial fan systems, dominated by high-energy channels and crevasse splay deposits, hence a faunal and environmental turnover is observed. The Pyrenean biostratigraphical data show similarities with those of the nearby Western Te- thys basins, and can be tentatively correlated with North African and European basins. The Triassic Pyrenean fossil remains might rank among the oldest continental records of the Western Tethys, providing new keys to decipher the Triassic faunal biogeography and recovery.
The continental Permian-Triassic transition in southern Europe presents little paleontological ev... more The continental Permian-Triassic transition in southern Europe presents little paleontological evidence of the Permian mass extinction and the subsequent faunal recovery during the early stages of the Triassic. New stratigraphic, sedimentological and paleontological analyses from Middle-Upper Permian to Lower-Middle Triassic deposits of the Catalan Pyrenees (NE Iberian Peninsula) allow to better constrain the Permian-Triassic succession in the Western Tethys basins, and provide new (bio-) chronologic data. For the first time, a large vertebra attributed to a caseid synapsid from the ?Middle Permian is reported from the Iberian Peninsula - one of the few reported from western Europe. Osteological and ichnological records from the Triassic Buntsandstein facies reveal a great tetrapod ichnodiversity, dominated by small to medium archosauromorphs and lepidosauromorphs (Rhynchosauroides cf. schochardti, R. isp. 1 and 2, Prorotodactylus-Rotodactylus, an undetermined Morphotype A and to a lesser degree large archosaurians (chirotheriids), overall suggesting a late Early Triassic-early Middle Triassic age. This is in agreement with recent palynological analyses in the Buntsandstein basal beds that identify different lycopod spores and other bisaccate and taeniate pollen types of late Olenekian age (Early Triassic). The Permian caseid vertebra was found in a playa-lake setting with a low influence of fluvial water channels and related to the distal parts of alluvial fans. In contrast, the Triassic Buntsandstein facies correspond to complex alluvial fan systems, dominated by highenergy channels and crevasse splay deposits, hence a faunal and environmental turnover is observed. The Pyrenean biostratigraphical data show similarities with those of the nearby Western Tethys basins, and can be tentatively correlated with North African and European basins. The Triassic Pyrenean fossil remains might rank among the continental oldest records of the Western Tethys, providing new keys to decipher the Triassic faunal biogeography and recovery.
A new Triassic actinopterygian specimen including the skull and the anterior portion of the squam... more A new Triassic actinopterygian specimen including the skull and the anterior portion of the squamation is described. The specimen represents the first find of a colobodontid from the Muschelkalk of Odèn locality (Pyrenean Basin, NE Iberian Peninsula). Although fragmentarily preserved in part and counterpart, the specimen shows considerable morphological details and fine preservation of bone structure. Comparisons to several well-known species of Colobodus AgAssiz, 1844 and Crenilepis Dames, 1888 from the Middle Triassic of the Besano Formation (northern Italy and southern Switzerland) and two specimens from Alcover outcrops (Catalonian Basin, NE Iberian Peninsula) previously assigned to Perleidus giganteus Beltan, 1972 enables a taxonomical re-assessment of Iberian colobodontids. The three specimens from the Iberian Peninsula are transferred to the genus Colobodus and re-named as Colobodus giganteus (Beltan, 1972) comb. nov. This taxon is the largest within the genus Colobodus and it is characterized by three diagnostic features: the series of supraorbitals, with more numerous and small ossifications in comparison with the rest of Colobodus species; the branchiostegal rays, more slender than in C. bassanii; and the teeth on the jaw margins not as well developed as in all other species of Colobodus, despite its considerable size.
The Upper Cretaceous outcrops of Armuña (Segovia Province, Spain) yielded relatively abundant mat... more The Upper Cretaceous outcrops of Armuña (Segovia Province, Spain) yielded relatively abundant material of vertebrates during prospection and excavation in the second half of the 1980s. However, little has been published on these remains. A new analysis of the specimens from this upper Campanian site reveals the presence of some clades in the site for the first time (e.g., Dortokidae, Anguimorpha, Mosasauroidea). Furthermore, the material of the clades previously recognized there has been reviewed and described in more detail, with some previous systematic attributions confirmed and others refuted. Consequently, a relatively high local diversity has been identified. New taxa (i.e., a member of Anguimorpha and a eusuchian crocodyliform) are identified in Armuña, coexisting with other taxa previously described in other sites from the Iberoarmorican Realm. The vertebrates from Armuña confirm that the fauna from the Upper Cretaceous of the Iberian Peninsula is composed of a mixture of European endemic clades and lineages shared with other continents such as North America (e.g., anguimorphs) and Africa (e.g., bothremydids).
Cadurcogekko rugosus Augé, 2005 was described as a gekkotan lizard from the Eocene of France. A r... more Cadurcogekko rugosus Augé, 2005 was described as a gekkotan lizard from the Eocene of France. A revision of the material has revealed that the holotype, a nearly complete dentary, actually belongs to a scincid lizard, for which we erect the new genus Gekkomimus. The rest of material originally referred to C. rugosus is of undoubted gekkotan nature and is included in the new species Cadurcogekko verus, with the exception of a partial left dentary belonging to the iguanid lizard Cadurciguana hoffstetteri.
Cranial and postcranial remains from the Middle Triassic of the Northeastern part of the Iberian ... more Cranial and postcranial remains from the Middle Triassic of the Northeastern part of the Iberian Peninsula are reported and tentatively assigned to Procolophonidae. The finding is the first occurrence of a procolophonid parareptile in the Iberian Peninsula, representing the southernmost record of the group in Europe. The fossilbearing locality is dated as Anisian (Middle Triassic) and includes three tooth-bearing bones, two cranial bone fragments and one interclavicle. The mandible described herein includes nine teeth. No cusps or complete crowns are preserved, but sections of the teeth are available. The three anterior teeth progressively decrease in size from front to back, whereas the teeth from the fourth to the eighth position present the opposite trend. The last tooth (the ninth) is clearly reduced in comparison to the previous ones. A close relationship with Anomoiodon-Kapes is suggested, however, more material is required in order to assess the exact taxonomical determination of the Iberian remains. This finding is expected to shed some light on the geographical distribution of procolophonines.
The evolution of blanid amphisbaenians (Mediterranean worm lizards) is mainly inferred based on m... more The evolution of blanid amphisbaenians (Mediterranean worm lizards) is mainly inferred based on molecular studies, despite their fossils are common in Cenozoic European localities. This is because the fossil record exclusively consists in isolated elements of limited taxonomic value. We describe the only known fossil amphisbaenian skull from Europe – attributed to Blanus mendezi sp. nov. (Amphisbaenia, Blanidae) – which represents the most informative fossil blanid material ever described. This specimen, from the Middle Miocene of Abocador de Can Mata (11.6 Ma, MN7+8) in the Vallès- Penedès Basin (Catalonia, NE Iberian Peninsula), unambiguously asserts the presence of Blanus in the Miocene of Europe. This reinforces the referral to this genus of the previously-known, much more incomplete and poorly-diagnostic material from other localities of the European Neogene. Our analysis – integrating the available molecular, paleontological and biogeographic data – suggests that the new species postdates the divergence between the two main (Eastern and Western Mediterranean) extant clades of blanids, and probably precedes the split between the Iberian and North-Western African subclades. This supports previous paleobiogeographic scenarios for blanid evolution and provides a significant minimum divergence time for calibrating molecular analyses of blanid phylogeny.
Recent finds of tetrapod ichnites in the red-bed and volcaniclastic succession of the Iberian Pyr... more Recent finds of tetrapod ichnites in the red-bed and volcaniclastic succession of the Iberian Pyrenean Basin permits an assessment of the faunal diversity and palaeoenvironment of a late early Permian setting. The tetrapod ichnoassemblage is inferred with the aid of photogrammetry and constituted by Batrachichnus salamandroides, Limnopus isp., cf. Amphisauropus (these three ichnotaxa present associated swimming traces, assigned to Characichnos), cf. Ichniotherium, Dromopus isp., cf. Varanopus, Hyloidichnus isp. and Dimetropus leisnerianus. These ichnotaxa suggest the presence of temnospondyls, seymouriamorphs, diadectomorphs, araeoscelids, captorhinids and synapsid pelycosaurs as potential trackmakers. These faunas correlate to the late early Permian. Two ichnoassociations correspond to two different palaeoenvironments that were permanently or occasionally aquatic (meandering fluvial systems and unconfined runoff surfaces, respectively). Ichnotaxa in the fluvial system is more diverse and abundant than in the runoff surfaces system. The Iberian Pyrenean ichnoassemblage reveals the faunistic connection and similarities among nearing basins (Spain, southern France and Morocco) differing from the Central European basins (i.e. German Tambach Formation). Based on the palaeogeography and the climate models of the early Permian, we suggest the correlation of ichnofaunal composition with different palaeoclimate biomes. This results in a diffuse boundary of Gondwana–Laurasia land masses, indicating no geographic barriers but a possible climate control on the faunal distribution. Further studies, integrating data from distant tracksites, should refine these biome boundaries.
Gallotia stehlini is the only species of lacertid living in the canarian island of Gran Canaria (... more Gallotia stehlini is the only species of lacertid living in the canarian island of Gran Canaria (with exception of the recently introduced Gallotia atlantica). The identity of subfossil populations in all islands is still debated because many extinct species have been subsequently synonymised or their rank has changed. The presence of small specimens among material from La Isleta locality (Pleistocene) posed a problem regarding whether they corresponded to a juvenile of G. stehlini or to an adult of a small species now extinct in the island. Accordingly, a proper identification of subfossil material from Gran Canaria was important in its potential to highlight differences between the subfossil and extant populations that could reveal the presence of a different species or subspecies, or in assessing the presence of G. stehlini as a subfossil. We performed a deep study of subfossil remains of Gallotia from Gran Canaria for the first time in order to investigate the identity of the subfossil populations. The remains studied were collected in the late XIXth century from the classical locality of la Isleta and are housed at Museu de Geologia de Barcelona, but had not been previously reported or investigated. Other specimens from the same locality have been cited and shallowly described, but their identification as G. stehlini had a weak morphological basis. These previous vague descriptions of otherwise well-preserved specimens were a consequence of the presence of a crust covering the articulated bones, what precluded a proper observation of morphological details. We performed a Micro CT-Scan of one of the small previously unpublished specimens in order to provide an accurate account of the osteological characters and compare them with the states in different species of Gallotia. Our results indicate that this specimen unequivocally represents a juvenile of G. stehlini, and no evidence for the presence of a different species or subspecies has been identified. The exceptional preservation of the specimens from La Isleta suggest a high potential for investigating a subfossil population in Gran Canaria (including ontogenetic changes), but may necessarily rely in the acquisition of Micro CT-Scans of the remaining specimens.
Tetrapod footprints are the most abundant vertebrate record of the Late Paleozoic and therefore c... more Tetrapod footprints are the most abundant vertebrate record of the Late Paleozoic and therefore crucial in the understanding of early tetrapod locomotion, habitats, and evolution. The Early Permian ichnological record is known worldwide and particularly well represented. It is often encountered in red-bed deposits resulting from the aridization of Pangea. In this period, the Pyrenees (NE Iberian Peninsula) existed in the equatorial region of the supercontinent as sedimentary basins infilled by volcanosedimentary deposits. In the recent years, we analyzed several outcrops bearing abundant tetrapod trace fossils in the Catalan Pyrenees. As a result, we were able to identify a wide diversity of ichnomorphotypes attributed to temnospondyls, possible seymouriamorphs, possible diadectomorphs, araeoscelids, bolosaurids, captorhinids and synapsids. Of particular interest for the track maker’s behavior, we discovered three different forms of swimming traces, corresponding to the ichnogenus Characichnos and associated with small- and large-sized temnospondyls (Batrachichnus salamandroides and Limnopus sp., respectively), and possible seymouriamorphs (cf. Amphisauropus).These remains represent an excellent tool to deepen the understanding of early tetrapod locomotion. The swimming traces correspond to digit tip prints dragged over the surface, i.e., scratches. The ichnites occur in groups of two to four digit scratches, ranging in length from 5 to 60 mm. Scratches are mostly curved or slightly sinuous (sigmoidal), but sometimes also straight. These traits, together with the expulsion rims commonly observed in the posterior part, record the limb movement of the trackmakers. Moreover, several surfaces present transitions from walking to swimming traces. Trackways composed of scratches and rounded digit tip impressions display irregular patterns indicating a relatively buoyant gait of the trackmaker. In all, these early tetrapods were capable of both terrestrial and subaqueous locomotion, which permitted a wide environmental distribution and colonization of the continental realm.
La presente comunicación pretende dar a conocer el estado de conocimiento sobre las localidades f... more La presente comunicación pretende dar a conocer el estado de conocimiento sobre las localidades fosilíferas del Principado de Andorra, encargado por el Área de Investigaciones Históricas del Departamento de Patrimonio Cultural y Política Lingüística del Gobierno del Principado de Andorra a la empresa Igeotest SL, con el asesoramiento del Instituto de Paleontología Crusafont de Sabadell. El objetivo ha sido documentar la carta paleontológica del Principado y para ello se ha propuesto la protección de parte del territorio andorrano en base a un criterio de riesgo, existiendo al mismo tiempo por cada zona fosilífera una subdivisión en yacimiento (J1) y área de presunción paleontológica (J2). El trabajo se ha efectuado en cuatro fases de estudio: Fase 1: Vaciado bibliográfico de más de 70 referencias con el reconocimiento de 30 localidades fosilíferas en Andorra. Fase 2: Reconocimiento de campo, descartando localidades que no fueron fructíferas y añadiendo otras que no estaban citadas en la bibliografía, inventariando un total de 36 afloramientos fosilíferos repartidos en 16 yacimientos. Fase 3: Una vez situados los yacimientos fosilíferos en su contexto geológico se procedió a la valoración desde el punto de vista de la cantidad, estado de preservación y probabilidad de deterioro en un futuro. Con esta valoración se estimó el riesgo que presentan los yacimientos respecto a su conservación futura e interés de preservación. Paralelamente se ha estimado el área de presunción paleontológica que representan los yacimientos, siendo ésta un total de 800 Ha y representa el 1,7 % del territorio andorrano, cifra que denota la escasez de fósiles en el Principado. Fase 4: Gracias al proyecto de fundación Marcel Chevalier de Igeotest SL, se ha dotado al Patrimonio Cultural Nacional de un fondo lítico con 100 piezas fósiles representativas de los yacimientos inventariados para su futuro estudio. Para un futuro quedó una quinta fase de estudio, la cual consistía en efectuar una recopilación de la información y documentación de los fósiles de Andorra que se encuentran en manos de colecciones públicas, ya que la documentación bibliográfica ha dejado constancia de la existencia de personas e instituciones susceptibles de aportar información sobre este aspecto
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Papers by Arnau Bolet
Penedès Basin (Catalonia, NE Iberian Peninsula), unambiguously asserts the presence of Blanus in the Miocene of Europe. This reinforces the referral to this genus of the previously-known, much more incomplete and poorly-diagnostic material from other localities of the European Neogene. Our analysis – integrating the available molecular, paleontological and biogeographic data – suggests that the new species postdates the divergence between the two main (Eastern and Western Mediterranean) extant clades of blanids, and probably precedes the split between the Iberian and North-Western African subclades. This supports previous paleobiogeographic scenarios for blanid evolution and provides a significant minimum divergence time for calibrating molecular analyses of blanid phylogeny.
Penedès Basin (Catalonia, NE Iberian Peninsula), unambiguously asserts the presence of Blanus in the Miocene of Europe. This reinforces the referral to this genus of the previously-known, much more incomplete and poorly-diagnostic material from other localities of the European Neogene. Our analysis – integrating the available molecular, paleontological and biogeographic data – suggests that the new species postdates the divergence between the two main (Eastern and Western Mediterranean) extant clades of blanids, and probably precedes the split between the Iberian and North-Western African subclades. This supports previous paleobiogeographic scenarios for blanid evolution and provides a significant minimum divergence time for calibrating molecular analyses of blanid phylogeny.
We performed a deep study of subfossil remains of Gallotia from Gran Canaria for the first time in order to investigate the identity of the subfossil populations. The remains studied were collected in the late XIXth century from the classical locality of la Isleta and are housed at Museu de Geologia de Barcelona, but had not been previously reported or investigated. Other specimens from the same locality have been cited and shallowly described, but their identification as G. stehlini had a weak
morphological basis. These previous vague descriptions of otherwise well-preserved specimens were a consequence of the presence of a crust covering the articulated bones, what precluded a proper observation of morphological details. We performed a Micro CT-Scan of one of the small previously unpublished specimens in order to provide an accurate account of the osteological characters and compare them with the states in different species of Gallotia. Our results indicate that this specimen unequivocally represents a juvenile of G. stehlini, and no evidence for the presence of a different species or subspecies has been identified. The exceptional preservation of the specimens from La Isleta suggest a high potential for investigating a subfossil population in Gran Canaria (including ontogenetic changes), but may necessarily rely in the acquisition of Micro CT-Scans of the remaining specimens.
the equatorial region of the supercontinent as sedimentary basins infilled by volcanosedimentary deposits. In the recent years, we analyzed several outcrops bearing abundant tetrapod trace fossils in the Catalan Pyrenees. As a result, we were able to identify a wide diversity of ichnomorphotypes attributed to temnospondyls, possible seymouriamorphs, possible diadectomorphs, araeoscelids, bolosaurids, captorhinids and synapsids. Of particular interest for the track maker’s behavior, we discovered three different forms of swimming traces, corresponding to the ichnogenus Characichnos and associated with small- and large-sized temnospondyls (Batrachichnus salamandroides and Limnopus sp., respectively), and possible seymouriamorphs (cf. Amphisauropus).These remains represent an excellent tool to deepen the understanding of early tetrapod locomotion.
The swimming traces correspond to digit tip prints dragged over the surface, i.e., scratches. The ichnites occur in groups of two to four digit scratches, ranging in length from 5 to 60 mm. Scratches are mostly curved or slightly sinuous (sigmoidal), but sometimes also straight. These traits, together with the expulsion rims commonly observed in the posterior part, record the limb movement of the trackmakers.
Moreover, several surfaces present transitions from walking to swimming traces. Trackways composed of scratches and rounded digit tip impressions display irregular patterns indicating a relatively buoyant gait of the trackmaker. In all, these early tetrapods were capable of both terrestrial and subaqueous locomotion, which permitted a wide environmental distribution and colonization of the continental realm.