Osteology and phylogeny ofRobustichthys luopingensis, the largest holostean fish in the Middle Triassic
| Autor: | Guang-Hui Xu |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
010506 paleontology Evolution lcsh:Medicine 010603 evolutionary biology 01 natural sciences Halecomorphi General Biochemistry Genetics and Molecular Biology Holostei Sinamia Amiidae Ionoscopiformes Taxonomy 0105 earth and related environmental sciences biology Osteology Fossils General Neuroscience lcsh:R Parasphenoid Paleontology General Medicine biology.organism_classification Sister group Evolutionary biology Hyomandibula Paleoecology General Agricultural and Biological Sciences |
| Zdroj: | PeerJ PeerJ, Vol 7, p e7184 (2019) |
| ISSN: | 2167-8359 |
| Popis: | The extinct ray-finned fish taxonRobustichthys luopingensisfrom Luoping, eastern Yunnan, China represents the largest holostean known in the Middle Triassic. Despite its potential significance for investigating the holostean phylogeny and reconstructing the Triassic marine ecosystems,Robustichthyshas so far not been described in detail and its phylogenetic position within the Holostei was controversy. This study provides a redescription and revision ofRobustichthysbased upon a comparative study of eight type specimens and nine new specimens. Newly recognized information includes a toothed parasphenoid, a pair of premaxillae not pierced by the olfactory nerve, a splint-like quadratojugal, a hatchet-shaped hyomandibula, an hourglass-shaped symplectic, anterior and posterior ceratohyals, a complete series of branchiostegal rays, and sclerotic bones. A revised reconstruction ofRobustichthysis presented. Results of a cladistic analysis confirmedRobustichthysas an ionoscopiform within the Halecomorphi; the previous placements ofRobustichthysas a basal ginglymodian and Ionoscopidae as a basal amiiform clade are not supported. The sister group relationship between Sinamiinae (SinamiaandIkechaoamia) and Amiinae (AmiaandCyclurus) within the Amiidae is newly recognized. This revised topology provides new insights into the evolution and historical paleoecology of halecomorph fishes. |
| Databáze: | OpenAIRE |
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