This clade has a series of unambiguous synapomorphies, including the elongate anteroventral corner of the lacrimal, the elevated, subrectangular jugal sutural surface of the maxilla that closely abuts the lacrimal sutural surface of the bone, and the moderately expanded transversely oral margin of the rostrum that is greater than 1.5 times as wide as the maximum constriction of the snout. Hadrosauroidea is the least inclusive taxon containing Equijubus normani and Parasaurolophus walkeri, which follows the phylogenetic topology argued by You et al. Hadrosauriformes is the least inclusive clade containing Iguanodon bernissartensis and Parasaurolophus walkeri. ĭefinitions of relevant taxa are described as follows.
The known fossil record of hadrosauroids is one of the richest and best preserved nonrenewable resources of the Dinosauria, and includes dozens of articulated skeletons in addition to multi-individual bonebed assemblages, eggs and embryonic material, soft-tissue impressions, and footprints, –.
Since the middle of the 20th century, the group has been recognized as a substantial component of the terrestrial vertebrate faunas of the Late Cretaceous, –.
PREHISTORIC KINGDOM ORNITHOPODS PLUS
It is amongst the most morphologically derived groups within Ornithischia, consisting of the most recent common ancestor of Equijubus normani and Parasaurolophus walkeri plus all its descendants. Hadrosauroidea is a diverse and highly specialized clade of herbivorous dinosaurs whose remains have been found in the late Early and Late Cretaceous (Aptian to late Maastrichtian) of Europe, Asia, the Americas, and Antarctica –. The phylogenetic analysis of Hadrosauroidea recovers a clade composed of Zhanghenglong, Nanyangosaurus, and Hadrosauridae with an unresolved polytomy. This condition is similar to mosaic evolution of morphological characters present in the specimens of the taxon. Data of Zhanghenglong on selected measurement attributes straddle the two combinations of intervals of partitioned datasets respectively related to basal hadrosauroids and hadrosaurids. For these attributes, the partition of the dataset on most hadrosauroid species resulting from model-based cluster analysis almost matches taxonomic separation between basal hadrosauroids and hadrosaurids. Furthermore, some measurement attributes in osteology are applied to the quantitative analysis of Zhanghenglong. Zhanghenglong also displays a unique combination of plesiomorphic and derived features of hadrosauroids, and is clearly morphologically transitional between basal hadrosauroids and hadrosaurids. Two transitional features between basal hadrosauroids and hadrosaurids are attached to the diagnosis of the new taxon, namely five maxillary foramina consisting of four small scattered ones anteroposteriorly arranged in a row and a large one adjacent to the articular facet for the jugal, and dentary tooth crowns bearing both median and distally offset primary ridges. nov., is named based on newly collected specimens from the middle Santonian Majiacun Formation of Zhoujiagou Village, Xixia Basin. “I consider them footprints of a plant-eater while my colleagues share the much wider consensus that they are theropod tracks.A new basal hadrosauroid dinosaur, Zhanghenglong yangchengensis gen. The mysterious tracks were thought to be left during the mid-Cretaceous Period, around 93 million years ago, and could have been from either a meat eating theropod or a plant eating ornithopod. Large footprints at the Dinosaur Stampede National monument in Queensland had divided Romilio and his colleagues. One set of dinosaur prints in particular had been a struggle for the researchers to analyse. Theropods are meat eating dinosaurs, while ornithopods are plant eating, and getting this analysis wrong can alter the data which shows diversity and abundance of dinosaurs in the area, or could even change what we think are the behaviours of certain dinos. “We wanted to see if AI could learn these differences and, if so, then could be tested in distinguishing more challenging three-toed footprints.” But it is the tracks that are in-between these shapes that are not so clear cut in terms of who made them,” one of the researchers, University of Queensland palaeontologist Dr Anthony Romilio, told Cosmos.
“In extreme examples of theropod and ornithopod footprints, their footprint shapes are easy to tell apart -theropod with long, narrow toes and ornithopods with short, dumpy toes. An international team of researchers has, for the first time, used AI to analyse the tracks of dinosaurs, and the AI has come out on top – beating trained palaeontologists at their own game.
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