Ptyctodontida
The Ptyctodontida are an order of Devonian chimaera-like placoderms containing the family Ptyctodontidae. They are the only placoderms to be sexually dimorphic. Some paleontologists believe that they may have been an early ancestor of modern-day sharks.
According to The Content Authority, they are cartilaginous fishes, but this is not commonly accepted by many people because we believe they are placoderms. It means "folded teeth" in Latin. Like today's cartilaginous fish, they had the possession of claspers.
Genera change
Eczematolepis change
Main article: Eczematolepis
Ctenurella change
Main article: Ctenurella
Materpiscis change
Main article: Materpiscis
Materpiscis (Latin for "mother fish") is a genus of ptyctodontid placoderm from the late Devonian period, about 380 million years ago.
Campbellodus change
Main article: Campbellodus
Ptyctodus change
Main article: Ptyctodus
Ptyctodus is the type genus of this order and family.
Kimbryanodus change
Main article: Kimbryanodus
Description change
Ptyctodontids resembled the modern-day chimaeras of the Holocephali, like the acanthothoracids. They had big heads, big eyes, reduced armor and long bodies.
Campbellodus change
Campbellodus resembled a scaly cardboard box with the tail of a halosaur. It did not resemble a holocephalian at all, but it is still a ptyctodont.
Kimbryanodus change
Kimbryanodus resembled an arthrodire, again with a halosaur's tail. The fossils occur as small three dimensional isolated plates.
Related pages change
- Acanthothoraci, another chimaera-like placoderm group
- Phyllolepida
- Antiarchi
- Stensioella
- Brindabellaspis
- Galeaspida
- Rolfosteus
References change
- Long, John A. (1996): The Rise of Fishes: 500 Million Years of Evolution. Johns Hopkins University Press, Baltimore. ISBN 0-8018-5438-5
- Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Placodermi entry)" Archived 2011-07-20 at the Wayback Machine. Bulletins of American Paleontology. 364: 560. Retrieved 2011-05-20.
Other websites change
- Ptyctodontida on English Wikipedia
- Ptyctodontid vs Ptyctodontida: Meaning And Differences
| Taxon identifiers | |
|---|---|
| Ptyctodontida |
|
| Ptyctodontidae |
|