A large coelacanth, † Whiteia giganteus sp. nov., from the Triassic of Texas, USA, establishes a Pangean radiation of early Mesozoic actinistians

Palaeontologia Electronica

article

Chase D. Brownstein¹ 

[1] Yale University and Stamford Museum and Nature Center

关键词: Coelacanths;    Actinistia;    Fishes;    Phylogenetics;    Triassic;    new species;   

DOI  :  10.26879/1254

学科分类：社会科学、人文和艺术（综合）

来源: Palaeontologia Electronica

【 摘 要 】

100 million years ago). Among these are so-called living fossil fishes like gars, sturgeons, bichirs, and lungfishes. Perhaps the most famous of these are the coelacanths, which are today represented by only two species yet are known from a fossil record comprising over 400 million years of evolution. Despite the high morphological and body size disparity observable in extinct coelacanths, the total number of species belonging to the coelacanth lineage Actinistia remains very low. Here, I describe the skull of a new species of large-bodied coelacanth from the Late Triassic Dockum Group of Texas. †Whiteia giganteus sp. nov. is the most massive member of its genus and one of the largest known Triassic actinistians. Phylogenetic analysis shows that this clade is stemward of the divergence–Latimerioidei–that produced almost all coelacanth diversity after the Triassic. In turn, †W. giganteus substantiates a new episode of body size increase in the coelacanth total clade and suggests an unsampled degree of coelacanth diversity in the Triassic of the United States, which has previously produced only latimerioid fossils.

【 授权许可】

CC BY|CC BY-NC-SA