A new theropod dinosaur from the Callovian Balabansai Formation of Kyrgyzstan

Zoological Journal of the Linnean Society, Journal Year: 2024, Volume and Issue: 201(4)

Published: July 4, 2024

Abstract Recent fieldwork in the late Middle Jurassic Balabansai Formation of Kyrgyzstan has yielded a partial skeleton large theropod dinosaur. The material includes few bones skull (postorbital, quadratojugal), dorsal and sacral vertebrae, fragments pectoral girdle forelimbs, an almost complete pelvic hindlimbs, is here made type new taxon, Alpkarakush kyrgyzicus gen. et sp. nov. can be diagnosed by extremely developed orbital brow on postorbital, pneumatic opening leading into cavities neural arch from centroprezygodiapophyseal fossa posterior enclosed ventral sulcus manual phalanx II-1, narrow deep intercondylar groove anterior side distal femur, epicondylar crest femur that offset end. A second, fragmentary, smaller specimen same site represents taxon. Based long bone histology, subadult individual, whereas juvenile, possibly indicating gregarious behaviour. Phylogenetic analysis places Metriacanthosauridae, underlining diversity wide distribution this clade Asia.

Language: Английский

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Comparative analysis of vestibular ecomorphology in birds

Journal of Anatomy, Journal Year: 2017, Volume and Issue: 231(6), P. 990 - 1018

Published: Nov. 20, 2017

The bony labyrinth of vertebrates houses the semicircular canals. These sense rotational accelerations head and play an essential role in gaze stabilisation during locomotion. sizes shapes canals have hypothesised relationships to agility locomotory modes many groups, including birds, a burgeoning palaeontological literature seeks make ecological interpretations from morphology extinct species. Rigorous tests form-function for vestibular system are required support these interpretations. We test hypothesis that lengths, streamlines angles between related body size, wing kinematics flying style birds. To do this, we applied geometric morphometrics multivariate phylogenetic comparative methods dataset 64 three-dimensional reconstructions endosseous obtained using micro-computed tomography scanning bird crania. A strong relationship centroid size indicates larger birds longer compared with their evolutionary relatives. Wing manoeuvrability (and quantified brachial index) explain small additional portion variance size. also find evidence allometric shape change indicating major aspects avian determined by spatial constraints. braincase accommodates large brain, eye other tetrapods. Negative allometry structures means restriction space within is intense This may our observation planes deviate more strongly orthogonality than those mammals, especially agile, gliding mammals. Furthermore, little or kinematics. Overall, results suggest topological problem fitting long into spatially constrained important determining specifics agility. Our tentatively indicate link visual acuity proportional among suggests labyrinths tetrapods result generally high acuities, not directly ability fly. close dinosaurian relatives allow broad inferences about flight vision, but so far provide few specific insights detailed

Language: Английский

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A new Jurassic theropod from China documents a transitional step in the macrostructure of feathers

The Science of Nature, Journal Year: 2017, Volume and Issue: 104(9-10)

Published: Aug. 22, 2017

Language: Английский

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A New Basal Salamandroid (Amphibia, Urodela) from the Late Jurassic of Qinglong, Hebei Province, China

PLoS ONE, Journal Year: 2016, Volume and Issue: 11(5), P. e0153834 - e0153834

Published: May 4, 2016

A new salamandroid salamander, Qinglongtriton gangouensis (gen. et sp. nov.), is named and described based on 46 fossil specimens of juveniles adults collected from the Upper Jurassic (Oxfordian) Tiaojishan Formation cropping out in Hebei Province, China. The salamander displays several ontogenetically taxonomically significant features, most prominently presence a toothed palatine, coronoid, unique pattern hyobranchium adults. Comparative study with previously known extant salamandroids sheds light early evolution Salamandroidea, species-diverse clade Urodela. Cladistic analysis places as sister taxon to Beiyanerpeton, two taxa together form basalmost within Salamandroidea. Along recently reported Beiyanerpeton same geological formation neighboring Liaoning discovery indicates that morphological disparity had been underway for by Late time.

Language: Английский

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The evolution of the modern avian digestive system: insights from paravian fossils from the Yanliao and Jehol biotas

Palaeontology, Journal Year: 2019, Volume and Issue: 63(1), P. 13 - 27

Published: Nov. 6, 2019

Abstract The avian digestive system, like other aspects of biology, is highly modified relative to reptiles. Together these modifications have imparted the great success Neornithes, most diverse clade amniotes alive today. It important understand when and how modern system evolved among neornithine ancestors in order elucidate evolutionary this biology stem birds their closest dinosaurian relatives: Mesozoic Paraves. Although direct preservation soft tissue has not yet been reported, ingested remains anatomical location preserved articulated fossils hint at structure its abilities. Almost all data concerning evidence diet Paraves comes from either Upper Jurassic Yanliao Biota or Lower Cretaceous Jehol Biota, both which are known deposits north‐eastern China. Here, sum gleaned thousands exceptionally well‐preserved paravians interpreted with regards evolution feeding apparatus. This information suggests intrinsic differences between closely related lineages implying strong homoplasy that each lineage non‐ornithuromorph was specialized. Regardless, capabilities appear be limited Ornithuromorpha, although complete set derived characters restricted Neornithes.

Language: Английский

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