A Paleozoic stem hagfish Myxinikela siroka — revised anatomy and implications for evolution of the living jawless vertebrate lineages

@article{Miyashita2020APS,
  title={A Paleozoic stem hagfish Myxinikela siroka — revised anatomy and implications for evolution of the living jawless vertebrate lineages},
  author={Tetsuto Miyashita},
  journal={Canadian Journal of Zoology},
  year={2020},
  volume={98},
  pages={850-865}
}
Hagfishes and lampreys comprise cyclostomes, the earliest branching and sole surviving clade of the once diverse assemblage of jawless crown-group vertebrates. Lacking mineralized skeletons, both o... 
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The fossil record of agnathans now includes representatives of the myxinoids (hagfish) as well as lampreys, and Fossils of other jawless fishes, both skeletal and soft-bodied forms, are discussed.
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TLDR
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TLDR
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TLDR
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TLDR
A fossil record of lampreys has previously been unknown, but a new genus demonstrates the presence of this group in the Pennsylvanian, and the absence of hagfish characters in the fossil supports the view that the common ancestor of Lampreys and hagfishes lived prior to thePennsylvanian.
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TLDR
It is shown that the hagfish and lamprey chondrocrania can be compared perfectly at the level of modules corresponding to the craniofacial primordia constituting the cyclostome morphotype and its diversification in early vertebrate evolution.
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