Medullary bone-like tissue in the mandibular symphyses of a pterosaur suggests non-reproductive significance

Prondvai, Edina; Stein, Koen

doi:10.1038/srep06253

Cited by 23 publications

(43 citation statements)

References 65 publications

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“…These authors then concluded that the presence of MB could not be used for gender identification. However, the assignment of this pterosaur tissue to MB is dubious, in part because it was described only in mandibular symphyses, and was not identified in any postcrania examined 52 . In contrast, although MB occurs in some cranial material in a few birds, it is predominantly noted in the postcrania, specifically long bones (e.g.…”

Section: Discussionmentioning

confidence: 98%

“…Recently, MB was suggested to exist in pterosaurs, based upon purported histological similarity. Prondvai and Stein 52 claimed to have identified the tissue in mandibulae of both juvenile and adult specimens, and proposed a redefinition of MB to include endosteal tissues that did not play a role in reproduction. These authors then concluded that the presence of MB could not be used for gender identification.…”

Section: Discussionmentioning

confidence: 99%

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Chemistry supports the identification of gender-specific reproductive tissue in Tyrannosaurus rex

Schweitzer

Zheng

Zanno

et al. 2016

Sci Rep

474

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Medullary bone (MB), an estrogen-dependent reproductive tissue present in extant gravid birds, is texturally, histologically and compositionally distinct from other bone types. Phylogenetic proximity led to the proposal that MB would be present in non-avian dinosaurs, and recent studies have used microscopic, morphological, and regional homologies to identify this reproductive tissue in both theropod and ornithischian dinosaurs. Here, we capitalize on the unique chemical and histological fingerprint of MB in birds to characterize, at the molecular level, MB in the non-avian theropod Tyrannosaurus rex (MOR 1125), and show that the retention of original molecular components in fossils allows deeper physiological and evolutionary questions to be addressed.

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

Chemistry supports the identification of gender-specific reproductive tissue in Tyrannosaurus rex

Schweitzer

Zheng

Zanno

et al. 2016

Sci Rep

474

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“…) are represented by anterior symphyseal fragments, premaxillary rostra and a fragment from the articular region, belonging to medium‐sized azhdarchids (estimated wingspans between 3 and 5 m), dimensionally and morphologically similar to Azhdarcho (Bakhurina & Unwin ; Averianov ), Bakonydraco (Ősi et al . , ; Prondvai & Stein ), and the ‘Laño azhdarchid’ (Buffetaut ). None of these specimens overlap with the preserved portion of LPB R.2347 prohibiting further morphological comparisons.…”

Section: Discussionmentioning

confidence: 99%

Partial mandible of a giant pterosaur from the uppermost Cretaceous (Maastrichtian) of the Hațeg Basin, Romania

Vremir¹,

Dyke

Csiki-Sava

et al. 2018

LET

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We describe and interpret a posterior mandibular symphysis of a very large azhdarchid pterosaur. The specimen LPB (FGGUB) R.2347 exhibits a series of morphological characters present in both azhdarchid and tapejarid pterosaurs, suggesting a more basal position within the clade Azhdarchidae. This fossil was collected from Maastrichtian continental deposits near Vălioara in the Hațeg Basin, Romania, but cannot be confidently referred to the contemporaneous giant Hatzegopteryx thambema, also from Vălioara, due to the absence of overlapping skeletal elements. Remarkably, this mandibular symphysis shares a number of features the smaller azhdarchoid Bakonydraco galaczi from the Santonian of Hungary. Additional comparisons with previously described large‐sized azhdarchid mandibles indicate a certain degree of morphological and probably ecological disparity within the group. This specimen represents the largest pterosaur mandible ever found and provides insights into the anatomy of the enigmatic giant pterosaurs.

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“…The authors suggested that the size and morphology of mandibular symphysis would not be good indicators of skeletal maturity in pterosaurs. A second study published subsequently addressed another aspect of the same assembly, Prondvai & Stein (2014) studied the association validity of medullary tissue deposition with reproduction in specimens of B. galaczi.…”

Section: Paleohistological Research History Of Pterosaurmentioning

confidence: 99%

“…This tissue has also been identifi ed in non-avian dinosaurs, in which its presence is considered to be a reliable indicator of female sexual maturity. Prondvai & Stein (2014) have suggested, however, a non-reproductive meaning for the medullary tissue pterosaurs, indicating that their presence may be associated with other mechanisms, such as physiological regulation.…”

Section: Paleohistological Research History Of Pterosaurmentioning

confidence: 99%

Biomechanical and physiological influences on the osteohistological deposition of Anhangueria (Pterosauria, Pterodactyloidea)

Eleutério¹,

Bantim²,

Lima³

et al. 2015

Rev. bras. paleontol.

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-The study of bone microstructure preserved in fossils provides substantial information about physiology, growth gradients and strategies, and some ecological considerations. Paleohistology is a useful tool for understanding the biological mechanisms of extinct animals. Presented here is the microstructure characterization of two Anhangueria pterosaurs. Thin sections of the fi rst wing phalanx and metacarpal IV of MN 7060-V have been confectioned, as have sections of the radius, ulna and fi rst wing phalanx of MPSC R2090. The histological analysis of bones of MN 7060-V revealed fi brolamellar tissue, few osteocytes and vascular canals. Bones of MPSC R2090 showed a mixed plexiform-fi brolamellar tissue and histovariability, showing that bones from the same individual grew in different patterns. The vascularization was high in the phalanx, intermediate in the ulna and absent in the radius. The absence of canals in the radius may be related to biomechanical issues, due to torsion resistance during fl ight. The histology and the absence of fused bones suggests that the specimens are not adults. Two distinct moments of growth were established. MN 7060-V is a subadult, with presence of bone porosity and MPSC R2090 is a young animal as determined by the high number of canals and plexiform-fi brolamellar tissues, which indicates fast growth. In this work, we concluded that in the Anhangueria clade, the growth of bones is not compatible with the ontogenetic stage. Young animals may present large proportions, whereas there were older individuals of smaller sizes in the same clade.Key words: paleohistology, Pterosauria, Anhangueria, Romualdo Formation, Araripe Basin.RESUMO -O estudo da microestrutura óssea preservada em organismos fósseis traz informações substanciais sobre a fi siologia, gradientes e estratégias de crescimento e uma série de considerações ecológicas. Para o entendimento dos mecanismos biológicos de animais extintos utiliza-se a paleohistologia. Apresentamos a caracterização microestrutural de dois pterossauros do clado Anhangueria. Foram confeccionadas lâminas da primeira falange alar e IV metacarpal de MN 7060-V, além da ulna, rádio e primeira falange alar de MPSC R2090. A análise histológica de ambos os ossos de MN 7060-V exibiu tecido fi brolamelar, poucos osteócitos e canais. Já os ossos de MPSC R2090 apresentaram tecido fi brolamelar plexiforme e histovariabilidade, sugerindo diferentes taxas de crescimento para os ossos de um mesmo indivíduo. A vascularização na falange foi elevada, intermediária na ulna e ausente no rádio. Essa ausência de canais pode estar relacionada a pressões biomecânicas, devido a resistência às cargas de torção exercidas durante o voo. A histologia e a ausência de fusão dos ossos sugerem indivíduos não adultos. Dois momentos diferentes de crescimento foram então estabelecidos. MN 7060-V é um subadulto, com presença de porosidade óssea e MPSC R2090 um jovem, devido à alta vascularização e tecido fi brolamelar plexiforme, indicativo de crescimento rápido. Foi concluído...

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Medullary bone-like tissue in the mandibular symphyses of a pterosaur suggests non-reproductive significance

Cited by 23 publications

References 65 publications

Chemistry supports the identification of gender-specific reproductive tissue in Tyrannosaurus rex

Chemistry supports the identification of gender-specific reproductive tissue in Tyrannosaurus rex

Partial mandible of a giant pterosaur from the uppermost Cretaceous (Maastrichtian) of the Hațeg Basin, Romania

Biomechanical and physiological influences on the osteohistological deposition of Anhangueria (Pterosauria, Pterodactyloidea)

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