10-549: Polacanthinae is a subfamily of ankylosaurs , most often nodosaurids , from the Late Jurassic through Early Cretaceous of Europe and potentially North America and Asia . The group is defined as the largest clade closer to Polacanthus foxii than Nodosaurus textilis or Ankylosaurus magniventris , as long as that group nests within either Nodosauridae or Ankylosauridae . If Polacanthus , and by extent Polacanthinae, falls outside either family-level clade, then
20-601: A tail vertebra, ribs, a left ilium (the main bone of the hip), and bony armor recovered from the Hekou Group in the Lanzhou-Minhe Basin. The animal's armor includes part of a "sacral shield", a carpet of osteoderms over the hips found in some other ankylosaurians . Taohelong was named and described in 2013 by Yang Jing-Tao, You Hai-Lu, Li Da-Qing, and Kong De-Lai. The type species is Taohelong jinchengensis . The generic name means "dragon ( long ) of
30-1006: A valid subfamily at the base of Nodosauridae. In the act of formally defining Polacanthinae in line with the requirements of the PhyloCode , Madzia and colleagues chose for the analysis of Yang et al. (2013) to be the primary reference for Polacanthinae, supplemented by similar results found by Kirkland (1998), Thompson et al. (2012), Arbour et al. (2016), Rivera-Sylva et al. (2018), and Zheng et al. (2018). Antarctopelta Mymoorapelta Anoplosaurus Hylaeosaurus Tatankacephalus Horshamosaurus Zhejiangosaurus Struthiosaurus languedocensis Struthiosaurus austriacus Hungarosaurus Animantarx Niobrarasaurus Nodosaurus Pawpawsaurus Sauropelta Silvisaurus Stegopelta Texasetes Edmontonia Panoplosaurus Hoplitosaurus Gargoyleosaurus Gastonia Peloroplites Taohelong Polacanthus While
40-498: The -inae suffix would be inappropriate, and the proper name for the group would be the informally defined Polacanthidae . Polacanthines were somewhat more lightly armoured than more advanced ankylosaurids and nodosaurids. Their spikes were made up of thin, compact bone with less reinforcing collagen than in the heavily armoured nodosaurids. The relative fragility of polacanthine armour suggests that it may have been as much for display as defense. They appear to have become extinct about
50-525: The clade is frequently referenced in literature, a majority of taxa considered to be polacanthines have instead been found to not form any natural groups with Polacanthus , representing both primitive nodosaurids, primitive ankylosaurids, or outside the Nodosauridae-Ankylosauridae clade. In the analysis of Arbour et al. in 2016 , and its subsequent modifications by Rivera-Sylva et al. and Zheng et al. in 2018 , only Hoplitosaurus
60-406: The details below. Request from 172.68.168.226 via cp1108 cp1108, Varnish XID 258845951 Upstream caches: cp1108 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 11:01:01 GMT Taohelong Taohelong is a genus of nodosaurid dinosaur known from Lower Cretaceous rocks in north-central China. Taohelong is based on Gansu Dinosaur Museum (GSDM) 00021, fossils including
70-745: The family Ankylosauridae, and he additionally referred Hoplitosaurus and Hylaeosaurus to the subfamily, though they were too incomplete to analyze. Kenneth Carpenter resurrected the name Polacanthidae for a similar group which he also found to be closer to ankylosaurids than to nodosaurids. Carpenter became the first to define Polacanthidae as all dinosaurs closer to Gastonia than to either Edmontonia or Euoplocephalus . Most subsequent researchers placed polacanthines as primitive ankylosaurids, though mostly without any rigorous study to demonstrate this idea. The first comprehensive study of 'polacanthid' relationships, published in 2011, found that they are either an unnatural grouping of primitive nodosaurids, or
80-405: The river ( he ) Tao". The specific name refers to the provenance at Jincheng. The describers established some diagnostic traits. The neural channel of the tail vertebra has a cross-section like an inverted trapezium. In top view the profile of the outer rim of the ilium is like a mirrored "S". The osteoderms of the sacral shield are irregular in both shape and size. Taohelong was placed in
90-517: The same time a land bridge opened between Asia and North America. The family Polacanthidae was named by Ernst Jaekel in 1910 to refer to a group of ankylosaurs which seemed to him intermediate between the ankylosaurids and nodosaurids. This grouping was ignored by most researchers until the late 1990s, when it was used as a subfamily (Polacanthinae) by Kirkland for a natural group recovered by his 1998 analysis suggesting that Polacanthus , Gastonia , and Mymoorapelta were closely related within
100-558: Was resolved as a polacanthine alongside Polacanthus , with Peloroplites and Taohelong falling within Nodosaurinae, Gargoyleosaurus , Gastonia , and Mymoorapelta being more basal nodosaurids outside both subclades, and Hylaeosaurus representing an early-diverging ankylosaurid. Ankylosaur Too Many Requests If you report this error to the Wikimedia System Administrators, please include
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