Alienacanthus
From Wikipedia, the free encyclopedia
| Alienacanthus Temporal range: Famennian, | |
|---|---|
 | |
| A. malkowskii and Hadrosteus | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | †Placodermi |
| Order: | †Arthrodira |
| Suborder: | †Brachythoraci |
| Family: | †Selenosteidae |
| Genus: | †Alienacanthus Kulczycki, 1957 |
| Type species | |
| †Alienacanthus malkowskii Julian Kulczycki, 1957 | |
Alienacanthus (/æliˌiːnəˈkænθəs/) (meaning "alien spine") is a genus of selenosteid placoderm from the Famennian Ostrówka Quarry in the Świętokrzyskie Mountains, Poland, and Kowala Quarry along with the Maïder Basin in the Anti-Atlas, Morocco. The type and only species is A. malkowskii, known from a handful of specimens.[1]
Alienacanthus' holotype, MZ VIII Vp-45, was referred to A. malkowskii in 1957 by Kulczycki, (1957). It consists of what were originally interpreted as "fragments of large osseous spines".[1] However two epitypes described by Jobbins et al., (2024) that preserve more material shows that what Kulczycki, (1957) interpreted as "spines" are in fact fragmentary inferognathals.[2] The epitypes, PIMUZ A/I 5239 and MCD 201, both comprise "a nearly complete articulated skull with all gnathal elements." and "left side of partially preserved skull with all gnathal elements." respectively.[2] The combination of a short upper jaw and elongated lower jaw is a striking case of convergent evolution with halfbeaks.[2] Alienacanthus was likely piscivorous, with jaws bearing sharp, posteriorly recurved teeth on both its upper and lower jaws, suggesting a grasping and trapping live prey.
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