Atoposaurid braincase from Upper Jurassic of Portugal + Taphrosphys neuroanatomy + Zygosaurus growth + Age of the Tetrapod Mastodonsaurus Fauna + more
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Ben Creisler
Oct 27, 2025, 5:23:21 PM (10 days ago) Oct 27
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Ben Creisler
Marcos Martín-Jiménez, Javier Catalá Montolio & Adán Pérez-García (2025)
First neuroanatomical study of the Paleocene bothremydid turtle Taphrosphys (Pleurodira), based on a skull of the Moroccan Taphrosphys ippolitoi, and implications for the marine lifestyle in Taphrosphyini
Swiss Journal of Palaeontology 144: 66
doi: https://doi.org/10.1186/s13358-025-00401-5
https://link.springer.com/article/10.1186/s13358-025-00401-5
Taphrosphyini is a diverse and geographically widely distributed lineage of bothremydid pleurodiran turtles. The first neuroanatomical reconstruction of the Paleogene genus of Taphrosphyini Taphrosphys is presented here, based on the study of a skull of the Moroccan Paleocene species Taphrosphys ippolitoi. Some osseous characters hitherto undocumented for this taxon are recognized in this specimen. Thus, among other anatomical elements, the postorbitals are documented for first time in this taxon, and the columella auris is described for the first time within Taphrosphyini. The use of the CT methodology and the three-dimensional modelling software allowed us to generate the three-dimensional virtual reconstruction of an idealized skull of Taphrosphys ippolitoi. This allows us to recognize several internal cranial structures and compare them with those of the other species of this genus. Most neuroanatomical elements of Taphrosphys ippolitoi are documented here. In addition of characters shared with all other bothremydids, others, shared exclusively with some representatives of this clade, are recognized as evidence for evaluate its lifestyle. The enlarged nasal cavity and the relatively high and wide semicircular canals of the endosseous labyrinth, confirmed here for Taphrosphyini, are convergent with those of other pleurodires identified as marine forms, including the Nigeremydini bothremydids. Thus, these and other anatomical and neuroanatomical traits observed in Taphrosphys ippolitoi are recognized as adaptative responses to marine environments.
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Recent reptile and tetrapod papers:
Free pdf:
E. Puértolas-Pascual (2025)
New dwarf crocodylomorph from the Upper Jurassic of Portugal and the first neuroanatomical data for Atoposauridae.
Fossil Record 28(2): 321-346.
doi: https://doi.org/10.3897/fr.28.167846
https://fr.pensoft.net/article/167846/
A new crocodylomorph fossil specimen (ML2631) from the Upper Jurassic of Lourinhã (Portugal) is described, based on a partially preserved skull table and braincase. The specimen was recovered from the Zimbral vertebrate microfossil assemblage, located in the lower part of the Praia Azul Member of the Lourinhã Formation (Kimmeridgian–Tithonian transition). The fossil was scanned using high-resolution micro-computed tomography (µCT), enabling the digital reconstruction of internal cranial structures, such as the brain cavity, cranial nerves, inner ear and paratympanic sinus system. These reconstructions represent the first neuroanatomical data ever reported for Atoposauridae, a clade of small-bodied neosuchian crocodylomorphs common in the Late Jurassic and Cretaceous of Europe.
Phylogenetic analysis places ML2631 within Atoposauridae and contributes to resolving previously uncertain relationships within the group. Although fragmentary, ML2631 exhibits a unique combination of anatomical features, including a dorsolaterally open cranioquadrate passage, a sagittal crest along the frontal and parietal, a large, posteriorly placed and septate choana, large supratemporal fenestrae with a distinct posterior fossa and a squamosal lobe bearing a discontinuous lateral groove. These traits, amongst others, distinguish ML2631 from all other known atoposaurid species. Additionally, its neuroanatomical proportions suggest a dwarf adult individual with low-frequency auditory sensitivity and moderate visual acuity, consistent with a primarily terrestrial or nearshore lifestyle, coherent with the depositional environment of the fossil site. Taken together, these results highlight the taxonomic and evolutionary relevance of the specimen and underline the importance of future discoveries of more complete material to confirm its systematic and phylogenetic status within Atoposauridae.
====
E. Puértolas-Pascual (2025)
New dwarf crocodylomorph from the Upper Jurassic of Portugal and the first neuroanatomical data for Atoposauridae.
Fossil Record 28(2): 321-346.
doi: https://doi.org/10.3897/fr.28.167846
https://fr.pensoft.net/article/167846/
A new crocodylomorph fossil specimen (ML2631) from the Upper Jurassic of Lourinhã (Portugal) is described, based on a partially preserved skull table and braincase. The specimen was recovered from the Zimbral vertebrate microfossil assemblage, located in the lower part of the Praia Azul Member of the Lourinhã Formation (Kimmeridgian–Tithonian transition). The fossil was scanned using high-resolution micro-computed tomography (µCT), enabling the digital reconstruction of internal cranial structures, such as the brain cavity, cranial nerves, inner ear and paratympanic sinus system. These reconstructions represent the first neuroanatomical data ever reported for Atoposauridae, a clade of small-bodied neosuchian crocodylomorphs common in the Late Jurassic and Cretaceous of Europe.
Phylogenetic analysis places ML2631 within Atoposauridae and contributes to resolving previously uncertain relationships within the group. Although fragmentary, ML2631 exhibits a unique combination of anatomical features, including a dorsolaterally open cranioquadrate passage, a sagittal crest along the frontal and parietal, a large, posteriorly placed and septate choana, large supratemporal fenestrae with a distinct posterior fossa and a squamosal lobe bearing a discontinuous lateral groove. These traits, amongst others, distinguish ML2631 from all other known atoposaurid species. Additionally, its neuroanatomical proportions suggest a dwarf adult individual with low-frequency auditory sensitivity and moderate visual acuity, consistent with a primarily terrestrial or nearshore lifestyle, coherent with the depositional environment of the fossil site. Taken together, these results highlight the taxonomic and evolutionary relevance of the specimen and underline the importance of future discoveries of more complete material to confirm its systematic and phylogenetic status within Atoposauridae.
====
Free pdf:
Marcos Martín-Jiménez, Javier Catalá Montolio & Adán Pérez-García (2025)
First neuroanatomical study of the Paleocene bothremydid turtle Taphrosphys (Pleurodira), based on a skull of the Moroccan Taphrosphys ippolitoi, and implications for the marine lifestyle in Taphrosphyini
Swiss Journal of Palaeontology 144: 66
doi: https://doi.org/10.1186/s13358-025-00401-5
https://link.springer.com/article/10.1186/s13358-025-00401-5
Taphrosphyini is a diverse and geographically widely distributed lineage of bothremydid pleurodiran turtles. The first neuroanatomical reconstruction of the Paleogene genus of Taphrosphyini Taphrosphys is presented here, based on the study of a skull of the Moroccan Paleocene species Taphrosphys ippolitoi. Some osseous characters hitherto undocumented for this taxon are recognized in this specimen. Thus, among other anatomical elements, the postorbitals are documented for first time in this taxon, and the columella auris is described for the first time within Taphrosphyini. The use of the CT methodology and the three-dimensional modelling software allowed us to generate the three-dimensional virtual reconstruction of an idealized skull of Taphrosphys ippolitoi. This allows us to recognize several internal cranial structures and compare them with those of the other species of this genus. Most neuroanatomical elements of Taphrosphys ippolitoi are documented here. In addition of characters shared with all other bothremydids, others, shared exclusively with some representatives of this clade, are recognized as evidence for evaluate its lifestyle. The enlarged nasal cavity and the relatively high and wide semicircular canals of the endosseous labyrinth, confirmed here for Taphrosphyini, are convergent with those of other pleurodires identified as marine forms, including the Nigeremydini bothremydids. Thus, these and other anatomical and neuroanatomical traits observed in Taphrosphys ippolitoi are recognized as adaptative responses to marine environments.
=====
Juliana Sterli & Evangelos Vlachos (2025)
Past, present, and future of southern Gondwanan turtles: a view from the South
Gondwana Research 150: 185-196
doi: https://doi.org/10.1016/j.gr.2025.09.013
https://www.sciencedirect.com/science/article/abs/pii/S1342937X25003028
Highlights
There are more than 600 occurrences of turtles in southern Gondwana.
Three phases of turtle evolution are recognized in southern Gondwana.
The evolution of southern Gondwanan turtles is tied to geotectonic changes.
Abstract
Extinct turtles from southern Gondwana are known from the 19th century. However, two-thirds of their knowledge has been produced during the last 30 years, changing notably our understanding of the evolution of the cheloniofauna of this region. Nowadays, there are more than 600 occurrences of turtles in southern Gondwana spanning from the Lower Jurassic until the Holocene. The aim of this work is to provide an updated account of the diversity and distribution of southern Gondwanan turtles and to test whether it is possible to recognize the three phases of evolution of continental turtles suggested for South America. We also compared the paleolatitudinal distribution of turtles between hemispheres, especially in temperate regions, showing that the fossil record is heavily skewed towards the north. The recent efforts have improved the southern Gondwanan fossil record, allowing for more complete diversity curves with evidence of a K/Pg extinction, but still, an important part of the past diversity is missing. In southern Gondwana, like in South America, the first two phases in the evolution of continental turtles, the Pangean and the Gondwanan, can be recognized in a similar fashion. However, the final part of the evolution of turtles in southern Gondwana differs in Patagonia and Australia + Zelandia because they have undergone different biogeographic histories. In Patagonia, chelids and meiolaniids became extinct after the middle Eocene, and it was not until the late Oligocene that tortoises arrived in South America, and that turtles roamed again in that region. On the contrary, in Australia, chelids and meiolaniids diversified during the Neogene, reaching distant islands in the case of meiolaniids. The Neogene-Recent Australian cheloniofauna is completed by the arrival of trionychids and carettochelyids from Asia.
Anton Uliakhin (2025)
Ontogenetic variation of the dissorophid Zygosaurus (Amphibia, Temnospondyli) from the Middle Permian of European Russia
Biological Communications 70(2): 139-151
DOI: https://doi.org/10.21638/spbu03.2025.206
https://biocomm.spbu.ru/article/view/19916
The paper is devoted to the temnospondyl amphibian Zygosaurus lucius from the Middle Permian of Bashkortostan, Russia. This species is one of the least known dissorophids. It was a fairly large form, ontogenetic variations of which were considered using two differently sized skulls as an example. Skull size was up to 350 mm. The study of morphology and morphometry showed the phylogenetic closeness of Zygosaurus to such dissorophids as Kamacops, Anakamacops and Cacops. As the size increased, the skull of Zygosaurus became more dorsoventrally flattened and wide, which is not typical for the ontogenesis of other Middle Permian temnospondyls, such as Archegosauroidea. The otic notch closed when it reached a size of at least 50 % of the maximum. Age-related changes in the skull of Zygosaurus may indirectly indicate a change in the type of ecological adaptation. Upon reaching half the maximum size, the relatively terrestrial lifestyle of Zygosaurus could have changed to a more semi-aquatic lifestyle, as presumed e. g., in the dissorophids Kamacops and Iratusaurus.
====
V. V. Silantiev, A. V. Kulikova, I. V. Novikov, A. S. Felker, D. N. Miftakhutdinova, R. R. Gabdullin, K. M. Akhmedenov, D. B. Yakupova, E. M. Nurieva & Ya. Ya. Saetgaleeva
The Age of the Tetrapod Fauna “Mastodonsaurus” (Middle Triassic) of the East European Platform: First U–Pb LA-ICP-MS Radioisotopic Dating Results. Article 1. Lithological Characteristics and Depositional Environment
Moscow University Geology Bulletin 80: 318–330
doi: https://doi.org/10.3103/S0145875225700449
https://link.springer.com/article/10.3103/S0145875225700449
This paper presents new data on the age of the Mastodonsaurus tetrapod fauna (Middle Triassic) of the East European Platform. The analysis of the section and ichnofossils showed that the sedimentation in the Eltonian time occurred mostly in continental conditions with episodic transgressions, whereas the Inderian time was characterized by gradual tectonic subsidence of the territory from the tidal beach zone to the sublittoral zone of a brackish water basin.
====
V. V. Silantiev, A. V. Kulikova, I. V. Novikov, A. S. Felker, D. N. Miftakhutdinova, R. R. Gabdullin, K. M. Akhmedenov, D. B. Yakupova, E. M. Nurieva & Ya. Ya. Saetgaleeva (2025)
The Age of the Tetrapod Mastodonsaurus Fauna (Middle Triassic) of the East European Platform: First Data on Radioisotope U–Pb LA-ICP-MS Dating. Article 2. Datings and Sedimentation Model
Moscow University Geology Bulletin 80: 499–510
doi: https://doi.org/10.3103/S0145875225700644
https://link.springer.com/article/10.3103/S0145875225700644
This article presents the first data on U–Pb LA-ICP-MS radioisotope dating of the Mastodonsaurus tetrapod fauna (Middle Triassic). The radioisotope age (241.6 ± 1.0 Ma) of the deposits, which directly underlie the beds of the Inderian Horizon with Mastodonsaurus fauna in the Kok-Tau section (Caspian basin), indicate that the basement of the Inderian Horizon approximately corresponds to the boundary of the Anisian and Ladinian stages and can be used as an approximate lower age limit of the distribution of this fauna. This radioisotope age, as well as the paleontological data on the Bukobai Horizon of South Urals, allows us to estimate the age of the Mastodonsaurus fauna as entirely Ladinian. A paleogeographic model of sedimentation conditions in the Elton and Inder periods is proposed.
====
Gondwana Research 150: 185-196
doi: https://doi.org/10.1016/j.gr.2025.09.013
https://www.sciencedirect.com/science/article/abs/pii/S1342937X25003028
Highlights
There are more than 600 occurrences of turtles in southern Gondwana.
Three phases of turtle evolution are recognized in southern Gondwana.
The evolution of southern Gondwanan turtles is tied to geotectonic changes.
Abstract
Extinct turtles from southern Gondwana are known from the 19th century. However, two-thirds of their knowledge has been produced during the last 30 years, changing notably our understanding of the evolution of the cheloniofauna of this region. Nowadays, there are more than 600 occurrences of turtles in southern Gondwana spanning from the Lower Jurassic until the Holocene. The aim of this work is to provide an updated account of the diversity and distribution of southern Gondwanan turtles and to test whether it is possible to recognize the three phases of evolution of continental turtles suggested for South America. We also compared the paleolatitudinal distribution of turtles between hemispheres, especially in temperate regions, showing that the fossil record is heavily skewed towards the north. The recent efforts have improved the southern Gondwanan fossil record, allowing for more complete diversity curves with evidence of a K/Pg extinction, but still, an important part of the past diversity is missing. In southern Gondwana, like in South America, the first two phases in the evolution of continental turtles, the Pangean and the Gondwanan, can be recognized in a similar fashion. However, the final part of the evolution of turtles in southern Gondwana differs in Patagonia and Australia + Zelandia because they have undergone different biogeographic histories. In Patagonia, chelids and meiolaniids became extinct after the middle Eocene, and it was not until the late Oligocene that tortoises arrived in South America, and that turtles roamed again in that region. On the contrary, in Australia, chelids and meiolaniids diversified during the Neogene, reaching distant islands in the case of meiolaniids. The Neogene-Recent Australian cheloniofauna is completed by the arrival of trionychids and carettochelyids from Asia.
===
Free pdf:
Anton Uliakhin (2025)
Ontogenetic variation of the dissorophid Zygosaurus (Amphibia, Temnospondyli) from the Middle Permian of European Russia
Biological Communications 70(2): 139-151
DOI: https://doi.org/10.21638/spbu03.2025.206
https://biocomm.spbu.ru/article/view/19916
The paper is devoted to the temnospondyl amphibian Zygosaurus lucius from the Middle Permian of Bashkortostan, Russia. This species is one of the least known dissorophids. It was a fairly large form, ontogenetic variations of which were considered using two differently sized skulls as an example. Skull size was up to 350 mm. The study of morphology and morphometry showed the phylogenetic closeness of Zygosaurus to such dissorophids as Kamacops, Anakamacops and Cacops. As the size increased, the skull of Zygosaurus became more dorsoventrally flattened and wide, which is not typical for the ontogenesis of other Middle Permian temnospondyls, such as Archegosauroidea. The otic notch closed when it reached a size of at least 50 % of the maximum. Age-related changes in the skull of Zygosaurus may indirectly indicate a change in the type of ecological adaptation. Upon reaching half the maximum size, the relatively terrestrial lifestyle of Zygosaurus could have changed to a more semi-aquatic lifestyle, as presumed e. g., in the dissorophids Kamacops and Iratusaurus.
====
V. V. Silantiev, A. V. Kulikova, I. V. Novikov, A. S. Felker, D. N. Miftakhutdinova, R. R. Gabdullin, K. M. Akhmedenov, D. B. Yakupova, E. M. Nurieva & Ya. Ya. Saetgaleeva
The Age of the Tetrapod Fauna “Mastodonsaurus” (Middle Triassic) of the East European Platform: First U–Pb LA-ICP-MS Radioisotopic Dating Results. Article 1. Lithological Characteristics and Depositional Environment
Moscow University Geology Bulletin 80: 318–330
doi: https://doi.org/10.3103/S0145875225700449
https://link.springer.com/article/10.3103/S0145875225700449
This paper presents new data on the age of the Mastodonsaurus tetrapod fauna (Middle Triassic) of the East European Platform. The analysis of the section and ichnofossils showed that the sedimentation in the Eltonian time occurred mostly in continental conditions with episodic transgressions, whereas the Inderian time was characterized by gradual tectonic subsidence of the territory from the tidal beach zone to the sublittoral zone of a brackish water basin.
====
V. V. Silantiev, A. V. Kulikova, I. V. Novikov, A. S. Felker, D. N. Miftakhutdinova, R. R. Gabdullin, K. M. Akhmedenov, D. B. Yakupova, E. M. Nurieva & Ya. Ya. Saetgaleeva (2025)
The Age of the Tetrapod Mastodonsaurus Fauna (Middle Triassic) of the East European Platform: First Data on Radioisotope U–Pb LA-ICP-MS Dating. Article 2. Datings and Sedimentation Model
Moscow University Geology Bulletin 80: 499–510
doi: https://doi.org/10.3103/S0145875225700644
https://link.springer.com/article/10.3103/S0145875225700644
This article presents the first data on U–Pb LA-ICP-MS radioisotope dating of the Mastodonsaurus tetrapod fauna (Middle Triassic). The radioisotope age (241.6 ± 1.0 Ma) of the deposits, which directly underlie the beds of the Inderian Horizon with Mastodonsaurus fauna in the Kok-Tau section (Caspian basin), indicate that the basement of the Inderian Horizon approximately corresponds to the boundary of the Anisian and Ladinian stages and can be used as an approximate lower age limit of the distribution of this fauna. This radioisotope age, as well as the paleontological data on the Bukobai Horizon of South Urals, allows us to estimate the age of the Mastodonsaurus fauna as entirely Ladinian. A paleogeographic model of sedimentation conditions in the Elton and Inder periods is proposed.
====
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