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Ornithosuchid trophic adaptations + bolosaurids from Eastern Europe + Cryptovaranoides + Cretaceous frogs from Brazil
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Ben Creisler
May 2, 2025, 1:07:07 PMMay 2
to DinosaurMa...@googlegroups.com
Ben Creisler
Some not yet mentioned tetrapod papers:
A re-examination of the holotype of Permotriturus herrei Tatarinov, 1968 (Tetrapoda, Bolosaurida), supplemented by a new specimen from the Isheevo type locality, Republic of Tatarstan, European Russia, supports the validity of the genus Belebey Ivakhnenko, 1973. The differences between the genera Belebey and Permotriturus are established in relationships of elements forming the suborbital portion of the skull roof, as well as in the pattern of the tooth implantation and jaw bone vasculature. Despite the specialized condition of the dental system of P. herrei and its uppermost (terminal Urzhumian) stratigraphic position in comparison with other bolosaurid species, the morphology of cheek region of this taxon exhibits more similarity with that of the lower Permian bolosaurids other than with members of the genus Belebey. The absence of clear diagnostic criteria currently prevents the subdivision of the order Bolosaurida into two families based on data on its middle Permian representatives.
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I. G. Danilov, A. P. Evsyutkin, D. V. Grigoriev & E. A. Zvonok (2025)
A Caudal Vertebra of a Giant Sea Turtle (Testudines: Chelonioidea) from the Upper Cretaceous Deposits of the Malyy Prolom Locality (Ryazan Region, Russia)
Paleontological Journal 59: 79–86
doi: https://doi.org/10.1134/S0031030124601531
https://link.springer.com/article/10.1134/S0031030124601531
This paper describes a caudal vertebra of a giant sea turtle, Chelonioidea indet., from the Upper Cretaceous Malyy Prolom locality (Ryazan Region, Russia; Middle Cenomanian–Middle Santonian). The caudal vertebra, probably IV–X, with a preserved length of 3.8 cm belonged to a turtle comparable in size to the type specimen of the protostegid Archelon ischyros from the Campanian of the Unites States. The proportions of the vertebral centrum suggest that it belonged to a female.
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Michael W. Caldwell, Chase D. Brownstein, Dalton L. Meyer, Simon G. Scarpetta, Michael S.Y. Lee, Tiago R. Simões (2025)
Cryptovaranoides is not a squamate
bioRxiv 2025.04.18.649532 (preprint)
doi: https://doi.org/10.1101/2025.04.18.649532
https://www.biorxiv.org/content/10.1101/2025.04.18.649532v1
Accurate reconstruction of the timescale of organismal evolution requires knowledge of the placement of extinct representatives among living branches. The fossil record has the capacity to reframe hypotheses of organismal evolution by producing representatives of clades that predate previously known fossils or node ages. Recently, one fossil with the potential to drastically change current consensus surrounding the timescale of reptile diversification was described from Triassic fissure-fill deposits in the United Kingdom. This taxon, Cryptovaranoides microlanius, was originally placed deep within the squamate crown clade, suggesting that many lineages of lizards and snakes must have appeared by the Triassic and implying long ghost lineages that paleontologists and molecular phylogeneticists have failed to detect using all other available data. Our team questioned this identification and instead suggested Cryptovaranoides had unclear affinities to living reptiles, but this alternative interpretation was again challenged by the team that originally described this species. Here, we dissect the morphological character codings used to support a crown squamate affinity for Cryptovaranoides microlanius and illustrate empirical problems with analyses that hypothesize this taxon to be a crown squamate. Our analyses emphasize the importance of stringency in constructing hypodigms of fossils, particularly when they may be key for proper time calibration of the Tree of Life.
South America hosts one of the largest diversities of living frogs in the world, but our knowledge of the group during the Mesozoic era is still limited. The Upper Cretaceous Bauru Group, in the south-central region of Brazil, has yielded a variety of vertebrate groups. Frog records are rare and restricted to a few well-preserved skeletons and fragmentary material. Nevertheless, they have offered important clues about the early diversification and distribution of frogs, especially among the speciose clade Neobatrachia. Here, we report new records of frogs from the Adamantina and Serra da Galga formations . The described specimens expand the geographical range of frogs in the Bauru Group and corroborate the hypothesis of a widespread distribution of neobatrachians in Gondwana landmasses by the Late Cretaceous. The discovery of the first putative Calyptocephalella-like form from a northern region in South America sheds light on the proposed biogeographic provincialism of frog faunas in South America by the Late Cretaceous.
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A. G. Sennikov (2025)
On Trophic Adaptations of Ornithosuchids (Archosauria)
Paleontological Journal 59: 87–99
doi: https://doi.org/10.1134/S0031030124601543
https://link.springer.com/article/10.1134/S0031030124601543
Ornithosuchidae differ from other carnivorous archosaurs in the unique morphology of the jaw apparatus and postcranial skeleton. Various, often opposite, points of view have been expressed regarding their trophic adaptations—from carnivory and scavenging to piscivory. The most reasonable hypothesis seems to be that ornithosuchids were medium sized hyperanisodont carnivorous macrophages. Moreover, there are some analogies between ornithosuchids and saber-toothed therapsids and mammals.
===
V. V. Bulanov (2025)
Towards a Revision of the Middle Permian Bolosaurids (Tetrapoda, Bolosaurida) of Eastern Europe
Paleontological Journal 59: 67 - 78
doi: https://doi.org/10.1134/S003103012460152X
https://link.springer.com/article/10.1134/S003103012460152X
A. G. Sennikov (2025)
On Trophic Adaptations of Ornithosuchids (Archosauria)
Paleontological Journal 59: 87–99
doi: https://doi.org/10.1134/S0031030124601543
https://link.springer.com/article/10.1134/S0031030124601543
Ornithosuchidae differ from other carnivorous archosaurs in the unique morphology of the jaw apparatus and postcranial skeleton. Various, often opposite, points of view have been expressed regarding their trophic adaptations—from carnivory and scavenging to piscivory. The most reasonable hypothesis seems to be that ornithosuchids were medium sized hyperanisodont carnivorous macrophages. Moreover, there are some analogies between ornithosuchids and saber-toothed therapsids and mammals.
===
V. V. Bulanov (2025)
Towards a Revision of the Middle Permian Bolosaurids (Tetrapoda, Bolosaurida) of Eastern Europe
Paleontological Journal 59: 67 - 78
doi: https://doi.org/10.1134/S003103012460152X
https://link.springer.com/article/10.1134/S003103012460152X
A re-examination of the holotype of Permotriturus herrei Tatarinov, 1968 (Tetrapoda, Bolosaurida), supplemented by a new specimen from the Isheevo type locality, Republic of Tatarstan, European Russia, supports the validity of the genus Belebey Ivakhnenko, 1973. The differences between the genera Belebey and Permotriturus are established in relationships of elements forming the suborbital portion of the skull roof, as well as in the pattern of the tooth implantation and jaw bone vasculature. Despite the specialized condition of the dental system of P. herrei and its uppermost (terminal Urzhumian) stratigraphic position in comparison with other bolosaurid species, the morphology of cheek region of this taxon exhibits more similarity with that of the lower Permian bolosaurids other than with members of the genus Belebey. The absence of clear diagnostic criteria currently prevents the subdivision of the order Bolosaurida into two families based on data on its middle Permian representatives.
=====
I. G. Danilov, A. P. Evsyutkin, D. V. Grigoriev & E. A. Zvonok (2025)
A Caudal Vertebra of a Giant Sea Turtle (Testudines: Chelonioidea) from the Upper Cretaceous Deposits of the Malyy Prolom Locality (Ryazan Region, Russia)
Paleontological Journal 59: 79–86
doi: https://doi.org/10.1134/S0031030124601531
https://link.springer.com/article/10.1134/S0031030124601531
This paper describes a caudal vertebra of a giant sea turtle, Chelonioidea indet., from the Upper Cretaceous Malyy Prolom locality (Ryazan Region, Russia; Middle Cenomanian–Middle Santonian). The caudal vertebra, probably IV–X, with a preserved length of 3.8 cm belonged to a turtle comparable in size to the type specimen of the protostegid Archelon ischyros from the Campanian of the Unites States. The proportions of the vertebral centrum suggest that it belonged to a female.
======
Free pdf:
Michael W. Caldwell, Chase D. Brownstein, Dalton L. Meyer, Simon G. Scarpetta, Michael S.Y. Lee, Tiago R. Simões (2025)
Cryptovaranoides is not a squamate
bioRxiv 2025.04.18.649532 (preprint)
doi: https://doi.org/10.1101/2025.04.18.649532
https://www.biorxiv.org/content/10.1101/2025.04.18.649532v1
Accurate reconstruction of the timescale of organismal evolution requires knowledge of the placement of extinct representatives among living branches. The fossil record has the capacity to reframe hypotheses of organismal evolution by producing representatives of clades that predate previously known fossils or node ages. Recently, one fossil with the potential to drastically change current consensus surrounding the timescale of reptile diversification was described from Triassic fissure-fill deposits in the United Kingdom. This taxon, Cryptovaranoides microlanius, was originally placed deep within the squamate crown clade, suggesting that many lineages of lizards and snakes must have appeared by the Triassic and implying long ghost lineages that paleontologists and molecular phylogeneticists have failed to detect using all other available data. Our team questioned this identification and instead suggested Cryptovaranoides had unclear affinities to living reptiles, but this alternative interpretation was again challenged by the team that originally described this species. Here, we dissect the morphological character codings used to support a crown squamate affinity for Cryptovaranoides microlanius and illustrate empirical problems with analyses that hypothesize this taxon to be a crown squamate. Our analyses emphasize the importance of stringency in constructing hypodigms of fossils, particularly when they may be key for proper time calibration of the Tree of Life.
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Fellipe Muniz, Ariovaldo Giaretta, Thiago S. Fachini, Thiago da Silva Marinho, Pedro Buck, Sabrina Rodrigues & Agustín G. Martinelli (2025)
New records of frogs (Anura, Lissamphibia) from the Late Cretaceous Bauru Group of Brazil and its paleobiogeographic implications
Cretaceous Research 106150
doi: https://doi.org/10.1016/j.cretres.2025.106150
https://www.sciencedirect.com/science/article/abs/pii/S0195667125000734
Highlights
We present new records of frogs for the Late Cretaceous of South America.
Neobatrachians were widely distributed in South America by the Late Cretaceous.
Calyptocephalellids were probably present in northern regions in the Late Cretaceous.
Incomplete material can help assess biogeographic patterns and guide future finds.
Abstract
New records of frogs (Anura, Lissamphibia) from the Late Cretaceous Bauru Group of Brazil and its paleobiogeographic implications
Cretaceous Research 106150
doi: https://doi.org/10.1016/j.cretres.2025.106150
https://www.sciencedirect.com/science/article/abs/pii/S0195667125000734
Highlights
We present new records of frogs for the Late Cretaceous of South America.
Neobatrachians were widely distributed in South America by the Late Cretaceous.
Calyptocephalellids were probably present in northern regions in the Late Cretaceous.
Incomplete material can help assess biogeographic patterns and guide future finds.
Abstract
South America hosts one of the largest diversities of living frogs in the world, but our knowledge of the group during the Mesozoic era is still limited. The Upper Cretaceous Bauru Group, in the south-central region of Brazil, has yielded a variety of vertebrate groups. Frog records are rare and restricted to a few well-preserved skeletons and fragmentary material. Nevertheless, they have offered important clues about the early diversification and distribution of frogs, especially among the speciose clade Neobatrachia. Here, we report new records of frogs from the Adamantina and Serra da Galga formations . The described specimens expand the geographical range of frogs in the Bauru Group and corroborate the hypothesis of a widespread distribution of neobatrachians in Gondwana landmasses by the Late Cretaceous. The discovery of the first putative Calyptocephalella-like form from a northern region in South America sheds light on the proposed biogeographic provincialism of frog faunas in South America by the Late Cretaceous.
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