Petalichthyida
Petalichthyida Temporal range: Early Lochkovian - Frasnian
| |
---|---|
Lunaspis | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | †Placodermi |
Order: | †Petalichthyida Jaeckel, 1911 |
Families | |
|
Petalichthyida is an
Because they had compressed body forms, it is speculated they were bottom-dwellers that chased after or ambushed smaller fish. Their diet is not clear, as none of the fossil specimens found have preserved mouthparts.
Taxonomy
According to Zhu's 1991 redescription of Diandongpetalichthys,[1] that genus represents the most basal petalichthyid known, as it has a comparatively elongated head, and shares certain anatomical features with acanthothoracids and primitive arthrodires such as the actinolepids. Quasipetalichthys, in turn, strongly resembles Diandongpetalichthys (aside from having a much more square-looking skull).
In Zhu's redescription, "Quasipetalichthyidae" (comprising Quasipetalichthys, Eurycaraspis, and possibly Neopetalichthys) and "Macropetalichthyidae" (comprising all the other "advanced" petalichthyid genera not including Neopetalichthys, or Diandongpetalichthys) form a dichotomy, with Diandongpetalichthys as a sister taxon.[2] Neopetalichthys is treated as an incertae sedis within Petalichthyida that may or may not be placed within or near Quasipetalichthyidae.
Timeline of genera
References
- ^ Zhu, M. "New information on Diandongpetalichthys (Placodermi: Petalichthyida)." Early vertebrates and related problems of evolutionary biology. Science Press, Beijing (1991): 179-192.
- ^ Zhu, Min & Wang, Junqing (October 1996). "A NEW MACROPETALICHTHYID FROM CHINA, WITH SPECIAL REFERENCE TO THE ZOOGEOGRAPHY OF THE MACROPETALICHTHYIDAE (PLACODERMI)" (PDF). Vertebrata PalAsiatica. 34 (4): 253–268.
Sources
- Long, John A. The Rise of Fishes: 500 Million Years of Evolution Baltimore: The Johns Hopkins University Press, 1996. ISBN 0-8018-5438-5
- Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Placodermi entry)". Bulletins of American Paleontology. 364: 560. Retrieved 2011-05-20.