Machimosauridae
Machimosauridae is an extinct family of teleosauroid thalattosuchian crocodyliforms.[1] The family was first identified in 2016,[2] when fossils of teleosauroid thalattosuchians, including an indeterminate close relative of Lemmysuchus and Machimosaurus, were described from the Middle Jurassic (Bathonian) of Morocco.[2] The family was largely expanded in 2020 when the systematics of Teleosauroidea were re-reviewed.[1] Members of this family generally were larger than the teleosaurids.[1]
| Machimosauridae | |
|---|---|
 | |
| Macrospondylus bollensis | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Suborder: | †Thalattosuchia |
| Superfamily: | †Teleosauroidea |
| Family: | †Machimosauridae Jouve et al., 2016 |
| Subgroups | |
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Classification
Machimosauridae is a diverse group of teleosauroids, phylogenetically defined as "the largest clade within Teleosauroidea containing Machimosaurus hugii, but not Plagiophthalmosuchus gracilirostris and Teleosaurus cadomensis."[1] The members of the Machimosauridae share several unique characters among teleosauroids, which are:[1]
- dorsally oriented external nares
- the premaxillary anterior and anterolateral margins are not sub-vertical and do not extend ventrally
- the premaxilla-maxilla suture is sub-rectangular and slightly interdigitating (most noticeably near the midline)
- no anterolateral expansion of the supratemporal fenestrae
- the postorbital is excluded from the orbit posteroventral margin
- a mostly horizontal pterygoid with a distinct posterolateral angle
- the cultriform process of the basisphenoid is exposed and bifurcates the pterygoids
The phylogenetic relationships of the Machimosauridae were analyzed in a comprehensive analysis of teleosauroid relationships. The results of the analysis are shown below:[1]
| Machimosauridae |
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Evolution
Machimosaurids underwent changes in body size and in feeding strategies throughout their evolutionary history, growing larger, more robust, and more specialized. Primitive machimosaurids, such as Macrospondylus and Charitomenosuchus, were longirostrine (long-snouted) generalists with body lengths less than 5 m (16 ft) long.[1][3] Machimosaurines originated in the Bathonian stage of the Middle Jurassic and simultaneously underwent a decrease in snout length but an increase in body size with Neosteneosaurus reaching up to 6.6 m (22 ft) long.[1][3] Machimosaurins were the largest teleosauroids, with body lengths up to 7.1 m (23 ft) (Machimosaurus rex), and were durophagous hunters, meaning they fed on hard prey.[1][3]
References
- Johnson, Michela M.; Young, Mark T.; Brusatte, Stephen L. (2020). "The phylogenetics of Teleosauroidea (Crocodylomorpha, Thalattosuchia) and implications for their ecology and evolution". PeerJ. 8: e9808. doi:10.7717/peerj.9808. ISSN 2167-8359.
Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. - Stéphane Jouve; Bastien Mennecart; Julien Douteau; Nour-Eddine Jalil (2016). "The oldest durophagous teleosauroid (Crocodylomorpha, Thalattosuchia) from the lower Bathonian of central High Atlas, Morocco". Palaeontology. 59 (6): 863–876. doi:10.1111/pala.12262.
- Young, Mark T.; Rabi, Márton; Bell, Mark A.; Foffa, Davide; Steel, Lorna; Sachs, Sven; Peyer, Karin. "Big-headed marine crocodyliforms and why we must be cautious when using extant species as body length proxies for long-extinct relatives". Palaeontologia Electronica. 19 (3): 1–14. doi:10.26879/648. ISSN 1094-8074.
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