A well‐preserved cranium from the Judith River Formation (Montana, USA) reveals the inner ear and neuroanatomy of a Campanian baenid turtle

The Anatomical Record, Год журнала: 2023, Номер 306(6), С. 1431 - 1451

Опубликована: Март 10, 2023

Abstract A cranium belonging to a baenid turtle was recently recovered from the lower half of Judith River Formation, Montana. Badlands Dinosaur Museum (BDM) 004 is well‐preserved partial that includes posterior cranial vault, base, and otic capsules. Based on diagnostic characters, skull can be attributed Plesiobaena antiqua , which has been previously reported Formation. It also shares with palatobaenines projecting processes tubercula basioccipitale prominent condylus occipitalis deep central pit, demonstrating variation within Pl. hypodigm. In phylogenetic analysis, an operational taxonomic unit BDM positioned Baenodda in unresolved polytomy Edowa zuniensis Palatobaeninae, Eubaeninae. Microcomputed tomographic (μCT) scans revealed morphology middle inner ear endocast are largely unknown baenids. Semicircular canals virtually identical those Eubaena cephalica consistent dimensions other taxa, including anterior semicircular robust taller than common crus diverge each at angle approximately 90°. The digital reveals moderately flexed brain rounded cerebral hemispheres minimal separation between metencephalon myelencephalon. Its columella auris (stapes) gracile posterodorsally flared basis columella. arcs across flattens near its terminus. This study adds understanding neuroanatomical expands morphological .

Язык: Английский

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The macroevolutionary and developmental evolution of the turtle carapacial scutes

Vertebrate Zoology, Год журнала: 2022, Номер 72, С. 29 - 46

Опубликована: Янв. 28, 2022

The scutes of the carapace extant turtles exhibit common elements in a narrow range topographical arrangements. typical arrangement has remained constant since its origin clade Mesochelydia (Early Jurassic), after period apparent greater diversity Triassic. This contribution is review development and evolutionary history scute patterns carapace, seen through lens recent developmental models. yields insights on pattern variations fossil record. We reinterpret “supracaudal” propose that Proganochelys had five vertebral scutes. discuss relationship between supramarginal Turing processes, we show how simple change during embryogenesis could account for configuration caudal region mesochelydians. also nature decrease number over course evolution, whether macroevolutionary trends can be discerned. argue with complete loss (e.g., softshells) follow clade-specific regimes, which are distinct from majority other turtles. Finally, draw parallel variation scale pileus (roof head) squamates. size numbers scales evolve wide range, but recognized tentative evidence convergence towards when become larger fewer. Thus, more general property similar systems integumentary appendages.

Язык: Английский

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Updated cranial and mandibular description of the Late Cretaceous (Maastrichtian) baenid turtle Saxochelys gilberti based on micro-computed tomography scans and new information on the holotype-shell association

Swiss Journal of Palaeontology, Год журнала: 2024, Номер 143(1)

Опубликована: Янв. 23, 2024

Saxochelys gilberti is a baenid turtle from the Late Cretaceous Hell Creek Formation of United States America known cranial, shell, and other postcranial material. Baenid turtles are taxonomically diverse common fossil elements within through Eocene faunas. Detailed anatomical knowledge critical to understanding systematics morphological evolution group. This particularly important as baenids represent an group continental vertebrates that survived mass extinction event associated with Cretaceous/Paleogene boundary. High-resolution micro-computed tomography scanning holotype skull reveals additional details for already well-known gilberti. includes revision some statements original description, but also detailed on internal features braincase description well-preserved axis (cervical vertebra 2). Our new previous work shell postcrania make one best-described, nearly complete turtles, which often only either isolated or cranial A revised phylogenetic analysis confirms position derived (Eubaeninae) more closely related Baena arenosa than Eubaena cephalica. The online version contains supplementary material available at 10.1186/s13358-023-00301-6.

Язык: Английский

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A description of a Denazinemys nodosa specimen (Testudinata, Baenidae) from the Late Cretaceous Kaiparowits Formation of southern Utah

Fossil record, Год журнала: 2023, Номер 26(2), С. 151 - 170

Опубликована: Июль 31, 2023

Denazinemys nodosa is a Late Cretaceous representative of the North American turtle clade Baenidae diagnosed, among others, by shell surface texture consisting raised welts. We provide detailed description partial skeleton from late Campanian Kaiparowits Formation Utah, USA, including bone-by-bone analysis its cranium based on images obtained using micro-computed tomography. A revised phylogenetic confirms placement close to Eubaena cephalica and Boremys spp. within Eubaeninae. Comparison with second skull previously assigned questions referral this taxon. An assortment specimens Early Mexico USA had been referred alone, even though characteristic known occur in other baenids. Our review all available material concludes that currently only New Utah.

Язык: Английский

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Mandibular anatomy of the paracryptodire Glyptops ornatus supports active hunting behavior in a Jurassic turtle

The Anatomical Record, Год журнала: 2023, Номер 307(6), С. 2007 - 2017

Опубликована: Сен. 25, 2023

The mandible of turtles is rich in osteological characters that are relevant for systematic purposes. Shape variation additionally reflects upon various feeding strategies and thus informative the palaeoecological interpretation extinct species based on fossils. mandibular anatomy non-baenid paracryptodires has so far been undescribed. Based digital segmentation a computed tomography scan, I herein describe pleurosternid paracryptodire Glyptops ornatus. This taxon slender gracile jaw, with weakly developed muscle attachment sites adductor muscles (i.e., fossa, coronoid process, retroarticular process) strongly reduced triturating ridges. These features typical suction-feeding aquatic hunters, thereby contrasting robust, durophagous-adapted mandibles many baenid or compsemydid paracryptodires. In addition, G. ornatus characterized by presence large splenial dorsal splenial-dentary contact, foramen, strong reduction foramen dentofaciale majus absence posterior intermandibular foramen.

Язык: Английский

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A new baenid, Edowa zuniensis gen. et sp. nov., and other fossil turtles from the Upper Cretaceous Moreno Hill Formation (Turonian), New Mexico, USA

Cretaceous Research, Год журнала: 2022, Номер 144, С. 105422 - 105422

Опубликована: Ноя. 24, 2022

Язык: Английский

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A new species of a snapping turtle ( Pan-Chelydridae / Chelydropsis ) from the Upper Miocene (MN9, early Vallesian) of Southwest Germany

Historical Biology, Год журнала: 2024, Номер unknown, С. 1 - 20

Опубликована: Май 7, 2024

Chelydropsis is a genus of the clade Pan-Chelydridae, which existed and was distributed in Eurasia from Eocene to end Pliocene. The fossil record North Alps particularly rich throughout Miocene. In this study, we describe new species Late Miocene (Vallesian, MN9) fossiliferous site Höwenegg southwestern Germany. based on nearly complete skeleton, stands out among best preserved most specimens ever found until now. species, heweneggensis sp. nov. particular importance. It differs coeval murchisoni, recent studies suggest only known have Europe Middle described herein thus adds diversity European Neogene record.

Язык: Английский

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The helochelydrid turtle Helochelydra nopcsai from the Early Cretaceous (late Barremian – early Aptian) fissure fills of Balve, North Rhine-Westphalia, Germany, including a large sample of granicones

Fossil record, Год журнала: 2023, Номер 26(1), С. 117 - 133

Опубликована: Июнь 2, 2023

Early Cretaceous (late Barremian – early Aptian) fissure fill deposits near Balve, North Rhine Westphalia, Germany, have yielded a rich continental vertebrate fauna over the course of last two decades. More than 250 fragmentary specimens, including more 150 osteoderms (i.e., granicones), represent late helochelydrid Helochelydra nopcsai , which had previously been reported from UK, France, and Spain. The new material mostly differs that type section by exhibiting reduced to absent entoplastral scute displaying distinct cranial sulci, both are interpreted as intraspecific variation. Although morphological insights limited, reveals visceral cavity extends anteriorly posteriorly bridge, relatively novel feature for an eclectic mix compsemydids, pleurosternids, other helochelydrids. available sample granicones great shape diversity, but morphometric analysis concludes no morphotypes exist.

Язык: Английский

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Peer Review #3 of "New insights into the cranial osteology of the Early Cretaceous paracryptodiran turtle Lakotemys australodakotensis (v0.2)"

Опубликована: Апрель 12, 2022

Lakotemys australodakotensis is an Early Cretaceous paracryptodire known from two shells and a skull the Lakota Formation of South Dakota, USA.Along with Arundelemys dardeni poorly Trinitichelys hiatti, generally retrieved as early branching baenid, but more insights into cranial anatomy these taxa needed to obtain better understanding paracryptodiran diversity evolution.Here, we describe using micro-computed tomography provide anatomical basis for future phylogenetic analyses that will be investigate precisely intrarelationships Paracryptodira.Preliminary comparisons reveal very similar Aptian-Albian basal baenid dardeni, both exhibit remarkable combination derived characters found in baenodds non-baenid paracryptodires, particularly Pleurosternidae, only date possess canal palatine artery.

Язык: Английский

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Peer Review #2 of "New insights into the cranial osteology of the Early Cretaceous paracryptodiran turtle Lakotemys australodakotensis (v0.1)"

Опубликована: Апрель 12, 2022

Lakotemys australodakotensis is an Early Cretaceous paracryptodire known from two shells and a skull the Lakota Formation of South Dakota, USA.Along with Arundelemys dardeni poorly Trinitichelys hiatti, generally retrieved as early branching baenid, but more insights into cranial anatomy these taxa needed to obtain better understanding paracryptodiran diversity evolution.Here, we describe using micro-computed tomography provide anatomical basis for future phylogenetic analyses that will be investigate precisely intrarelationships Paracryptodira.Preliminary comparisons reveal very similar Aptian-Albian basal baenid dardeni, both exhibit remarkable combination derived characters found in baenodds non-baenid paracryptodires, particularly Pleurosternidae, only date possess canal palatine artery.

Язык: Английский

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