Neotheropod specimen from Early Jurassic of Southwestern China
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Ben Creisler
May 8, 2026, 10:34:25 AM (9 days ago) May 8
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Ben Creisler
A new paper:
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Ranwei Wang, Lida Xing, Vladimir Nikolov, Tao Wang & Xing Xu (2026)
A new non-averostran neotheropod specimen from the Early Jurassic of Southwestern China and its implications for early theropod evolution
Zoological Journal of the Linnean Society 207(1): zlag062
doi: https://doi.org/10.1093/zoolinnean/zlag062
https://academic.oup.com/zoolinnean/article-abstract/207/1/zlag062/8672629
Averostra (= Ceratosauria + Tetanurae) is a crucial clade that includes nearly all theropods from the Toarcian (Early Jurassic) to the Late Cretaceous and ultimately gave rise to birds. Although recent discoveries have improved our understanding of the transition from non-averostran neotheropods to averostrans, many key fossils remain fragmentary, limiting further insight into this evolutionary sequence. Here, we describe a new neotheropod specimen from the Lower Jurassic Lufeng Formation of Yunnan, China. The specimen includes a postcranial skeleton, lacking cervical and dorsal vertebrae, with osteohistological data suggesting that it represents an immature individual. It is distinguished from other neotheropods, particularly referred specimens of Sinosaurus (e.g. KMV8701 and LDM-L10), by a unique combination of characters. However, owing to the absence of overlapping material with the sub-coeval Shuangbaisaurus anlongbaoensis, we refrain from naming a new species. Multiple phylogenetic analyses consistently recover the specimen as the sister taxon to Averostra. It retains many plesiomorphic non-averostran traits but also exhibits features approaching those of averostrans, illustrating the gradual morphological transition towards Averostra. Nonetheless, the presence of several tetanuran-like characters further underscores the complexity of early theropod evolution and suggests that some features traditionally regarded as diagnostic of Tetanurae originated before the emergence of Averostra.
A new non-averostran neotheropod specimen from the Early Jurassic of Southwestern China and its implications for early theropod evolution
Zoological Journal of the Linnean Society 207(1): zlag062
doi: https://doi.org/10.1093/zoolinnean/zlag062
https://academic.oup.com/zoolinnean/article-abstract/207/1/zlag062/8672629
Averostra (= Ceratosauria + Tetanurae) is a crucial clade that includes nearly all theropods from the Toarcian (Early Jurassic) to the Late Cretaceous and ultimately gave rise to birds. Although recent discoveries have improved our understanding of the transition from non-averostran neotheropods to averostrans, many key fossils remain fragmentary, limiting further insight into this evolutionary sequence. Here, we describe a new neotheropod specimen from the Lower Jurassic Lufeng Formation of Yunnan, China. The specimen includes a postcranial skeleton, lacking cervical and dorsal vertebrae, with osteohistological data suggesting that it represents an immature individual. It is distinguished from other neotheropods, particularly referred specimens of Sinosaurus (e.g. KMV8701 and LDM-L10), by a unique combination of characters. However, owing to the absence of overlapping material with the sub-coeval Shuangbaisaurus anlongbaoensis, we refrain from naming a new species. Multiple phylogenetic analyses consistently recover the specimen as the sister taxon to Averostra. It retains many plesiomorphic non-averostran traits but also exhibits features approaching those of averostrans, illustrating the gradual morphological transition towards Averostra. Nonetheless, the presence of several tetanuran-like characters further underscores the complexity of early theropod evolution and suggests that some features traditionally regarded as diagnostic of Tetanurae originated before the emergence of Averostra.
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Mickey Mortimer
May 9, 2026, 3:54:05 AM (8 days ago) May 9
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One cool thing about this paper is the creation of a name for the 'neotheropods closer to averostrans than coelophysoids' clade that increasingly seems to be where Dilophosaurus, Sinosaurus, Cryolophosaurus, etc. belong- Averostriformes.
"Averostriformes clade nov.
Definition (stem-based): All neotheropods more closely related to Allosaurus fragilis Marsh, 1877, than to Coelophysis bauri Cope, 1887."
Mickey Mortimer
"Averostriformes clade nov.
Definition (stem-based): All neotheropods more closely related to Allosaurus fragilis Marsh, 1877, than to Coelophysis bauri Cope, 1887."
Mickey Mortimer
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