New Data on Dinosaurs in the Late Cretaceous Sediments of the Southern Urals

Doklady Earth Sciences, Journal Year: 2022, Volume and Issue: 505(2), P. 562 - 564

Published: Aug. 1, 2022

Language: Английский

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The ontogenetic status of a small hadrosauroid dinosaur from the uppermost Cretaceous of Bulgaria, and implications for the paleobiogeography and assembly of European island faunas

Cretaceous Research, Journal Year: 2024, Volume and Issue: 157, P. 105819 - 105819

Published: Jan. 1, 2024

Language: Английский

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A Hadrosauroid Vertebra from the Upper Cretaceous Izumi Group, Kagawa Prefecture, Japan

Paleontological Research, Journal Year: 2024, Volume and Issue: 28(4)

Published: July 23, 2024

Of the four main Japanese islands, Late Cretaceous dinosaur fossils have been discovered in Hokkaido, Honshu, and Kyushu. Here, we report first from remaining island Shikoku, an isolated dorsal vertebra upper Campanian Hiketa Formation (Izumi Group) Sanuki, Kagawa Prefecture. The is incomplete, comprising a robust centrum with subrectangular profile that generally characteristic of dinosaurs. Histological examination reveals moderately packed trabecular bone complete absence pneumatic structures, which precludes referral specimen to Saurischia or Pterosauria. Instead, interpret it as hadrosauriform ornithischian based on slightly expanded anterior articular surface centrum; heart-shaped outline intervertebral surface, resulting its dorsally wide ventrally narrow shape; ventral keel; neural canal partially embedded into centrum. As positioning common Bactrosaurus higher taxa within Hadrosauriformes, tentatively refer Hadrosauroidea. This discovery provides additional evidence hadrosauriforms had dispersed present-day Japan by highlights potential provide improve our understanding diversity at extreme eastern continental margin Eurasia.

Language: Английский

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Individual, ontogenetic, and phylogenetic variation in the dentition of hadrosaurids (Iguanodontia: Ornithischia)

Journal of Systematic Palaeontology, Journal Year: 2024, Volume and Issue: 22(1)

Published: Nov. 25, 2024

Language: Английский

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Determination of individual age and ontogenetic stages of fossil tetrapods using paleohistological methods

Зоологический журнал, Journal Year: 2024, Volume and Issue: 103(6), P. 15 - 30

Published: Dec. 3, 2024

The determination of individual age and ontogenetic stage (juvenile, subadult, adult) fossil vertebrates is important for the initial taxonomic affiliation, as well further evolutionary paleobiological interpretations. Determination (= relative age) carried out by various methods, including paleohistological analysis. study thin sections tetrapod bones allows us to assume how many years animal lived (skeletochronological method) determine according a set age-related histological markers: change in type bone matrix vascularization, distance between growth marks, formation external fundamental system (EFS), inner (endosteal) outer (periosteal) circumferential layers (OCL, ICL), occurrences secondary remodeling – Haversian substitution trabeculae. Depending on phylogenetic position biological peculiarities group tetrapods, “histologic markers” may be different.

Language: Английский

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Evolutionary convergence in a small cursorial styracosternan ornithopod dinosaur from western Europe

Journal of Vertebrate Paleontology, Journal Year: 2022, Volume and Issue: 42(5)

Published: Nov. 25, 2022

A metatarsal IV from a hitherto unknown endemic small-bodied styracosternan is described uppermost Maastrichtian strata of NE Spain, part the Ibero-Armorican island Late Cretaceous European Archipelago. This element unique among fourth metatarsals all other ornithopods in combining greatly elongated proportions basally branching members clade with prominent medial flange seen styracosternans. specimen becomes holotype new genus and species. Histological data indicate that this individual was late subadult at time death, but not far reaching somatic maturity. By analogy elongate lightly built, cursorial ornithopods, it likely animal also capable rapid locomotion. consistent differential distribution intense bone remodeling IV, resulting biomechanical stress produced during hindlimb propelling. Notably, represents an exception to mediportality large body size characterize clade. The elongation inferred cursoriality, small constitute case evolutionary convergence distantly related non-iguanodontian dryosaurid elasmarian iguanodontians. Unlike regions world where, latest stages Cretaceous, herbivore ecological niche represented by non-iguanodontians non-hadrosauriforms, occupied styracosternan.

Language: Английский

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Evolution of Hadrosaurs in the Campanian of Laramidia: New Information from the Skull Roof and Braincase

Published: Jan. 1, 2022

This project seeks to investigate the morphology, ontogeny, and evolution of skull roof braincase characters in hadrosaurids from Campanian northern Laramidia (Alberta Montana), a setting which they have been historically recognized as having high abundance diversity. New material is evaluated clarify distribution informativeness morphological character states, allow further testing previous hypotheses about how ontogenetic development these evolved within clades, enable identification previously unrecorded taxa. Five partial skulls Maiasaura peeblesorum are described bone bed Two Medicine Formation Montana, providing basis for description morphology this taxon, an series allowing crest be compared related new middle unit Oldman at Milk River Ridge Reservoir near Warner, southern Alberta both represent first occurrences taxon that unit. The diagnostic occurrence Canada. Brachylophosaurus example co-occurring brachylophosaurins. second Parasaurolophini, oldest lambeosaurine Alberta. A phylogenetic analysis using maximum parsimony Bayesian methods supports identifications, also re-identifies specimen Dinosaur Park geologically youngest brachylophosaurin

Language: Английский

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Peer Review #1 of "Taphonomy and taxonomy of a juvenile lambeosaurine (Ornithischia: Hadrosauridae) bonebed from the late Campanian Wapiti Formation of northwestern Alberta, Canada (v0.1)"

Published: May 4, 2021

Hadrosaurid (duck-billed) dinosaur bonebeds are exceedingly prevalent in upper Cretaceous (Campanian-Maastrichtian) strata from the Midwest of North America (especially Alberta, Canada, and Montana, U.S.A) but less frequently documented more northern regions.The Wapiti Formation northwestern Alberta is a largely untapped resource terrestrial palaeontological information missing southern due to deposition marine Bearpaw Formation.In 2018, Boreal Dinosaur Project rediscovered Spring Creek Bonebed, which had been lost since 2002, along bank River, southwest Grande Prairie.Earlier excavations observations Bonebed suggested that site yielded young hadrosaurines.Continued work 2018 2019 recovered ~300 specimens included minimum eight individuals, based on number right humeri.The morphology several cranial elements unequivocally supports lambeosaurine affinities, making sample first occurrence lambeosaurines Formation.The overall size range histology bones found at indicate these animals were uniformly late juveniles, suggesting age segregation was life history strategy among hadrosaurids.Given considerable attained by lambeosaurines, they probably segregated breeding population during nesting or caring for young, rather than different diet locomotory requirements.Dynamic aspects history, such as segregation, may well have contributed highly diverse cosmopolitan nature Late hadrosaurids.

Language: Английский

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Peer Review #2 of "Taphonomy and taxonomy of a juvenile lambeosaurine (Ornithischia: Hadrosauridae) bonebed from the late Campanian Wapiti Formation of northwestern Alberta, Canada (v0.1)"

Published: May 4, 2021

Hadrosaurid (duck-billed) dinosaur bonebeds are exceedingly prevalent in upper Cretaceous (Campanian-Maastrichtian) strata from the Midwest of North America (especially Alberta, Canada, and Montana, U.S.A) but less frequently documented more northern regions.The Wapiti Formation northwestern Alberta is a largely untapped resource terrestrial palaeontological information missing southern due to deposition marine Bearpaw Formation.In 2018, Boreal Dinosaur Project rediscovered Spring Creek Bonebed, which had been lost since 2002, along bank River, southwest Grande Prairie.Earlier excavations observations Bonebed suggested that site yielded young hadrosaurines.Continued work 2018 2019 recovered ~300 specimens included minimum eight individuals, based on number right humeri.The morphology several cranial elements unequivocally supports lambeosaurine affinities, making sample first occurrence lambeosaurines Formation.The overall size range histology bones found at indicate these animals were uniformly late juveniles, suggesting age segregation was life history strategy among hadrosaurids.Given considerable attained by lambeosaurines, they probably segregated breeding population during nesting or caring for young, rather than different diet locomotory requirements.Dynamic aspects history, such as segregation, may well have contributed highly diverse cosmopolitan nature Late hadrosaurids.

Language: Английский

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Peer Review #3 of "Taphonomy and taxonomy of a juvenile lambeosaurine (Ornithischia: Hadrosauridae) bonebed from the late Campanian Wapiti Formation of northwestern Alberta, Canada (v0.1)"

Published: May 4, 2021

Hadrosaurid (duck-billed) dinosaur bonebeds are exceedingly prevalent in upper Cretaceous (Campanian-Maastrichtian) strata from the Midwest of North America (especially Alberta, Canada, and Montana, U.S.A) but less frequently documented more northern regions.The Wapiti Formation northwestern Alberta is a largely untapped resource terrestrial palaeontological information missing southern due to deposition marine Bearpaw Formation.In 2018, Boreal Dinosaur Project rediscovered Spring Creek Bonebed, which had been lost since 2002, along bank River, southwest Grande Prairie.Earlier excavations observations Bonebed suggested that site yielded young hadrosaurines.Continued work 2018 2019 recovered ~300 specimens included minimum eight individuals, based on number right humeri.The morphology several cranial elements unequivocally supports lambeosaurine affinities, making sample first occurrence lambeosaurines Formation.The overall size range histology bones found at indicate these animals were uniformly late juveniles, suggesting age segregation was life history strategy among hadrosaurids.Given considerable attained by lambeosaurines, they probably segregated breeding population during nesting or caring for young, rather than different diet locomotory requirements.Dynamic aspects history, such as segregation, may well have contributed highly diverse cosmopolitan nature Late hadrosaurids.

Language: Английский

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