Osteolaeminae is a subfamily of true crocodiles within the family Crocodylidae containing the dwarf crocodiles and slender-snouted crocodiles, and is the sister taxon to Crocodylinae.
| Osteolaeminae | |
|---|---|
| |
| West African dwarf crocodile (Osteolaemus tetraspis) | |
| |
| Central African slender-snouted crocodile (Mecistops leptorhynchus) | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Archosauromorpha |
| Clade: | Archosauriformes |
| Order: | Crocodilia |
| Family: | Crocodylidae |
| Subfamily: | Osteolaeminae Brochu, 2003 |
| Genera | |
Taxonomy
editOsteolaeminae was named by Christopher Brochu in 2003 as a subfamily of Crocodylidae separate from Crocodylinae, and is cladistically defined as Osteolaemus tetraspis (the Dwarf crocodile) and all crocodylians more closely related to it than to Crocodylus niloticus (the Nile crocodile).[2][3] This is a stem-based definition, and is the sister taxon to Crocodylinae. Osteolaeminae contains the two extant genera Osteolaemus and Mecistops, along with several extinct genera, although the number of extant species within Osteolaeminae is currently in question.[4]
Phylogeny
editThe cladogram below is based on two studies that combined morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data.[5][6]
| Crocodylidae |
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| (crown group) |
Alternatively, other morphological studies have recovered Mecistops as a basal member of Crocodylinae, more closely related to Crocodylus than to Osteolaemus and the other members of Osteolaeminae,[3][7] as shown in the cladogram below.[7]
| Crocodylidae |
|
Paleoafrican Crocodylus Neotropical Crocodylus Indo-Pacific Crocodylus | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Species list
edit- Subfamily Osteolaeminae
- Genus Osteolaemus
- Osteolaemus osborni, Osborn’s dwarf crocodile
- Osteolaemus tetraspis, dwarf crocodile (There has been controversy as to whether or not this is actually two species; recent (2010) DNA analysis indicate three distinct species: O. tetraspis, O. osborni and a third, currently unnamed.)[4]
- Genus Mecistops
- Genus Brochuchus†
- Brochuchus pigotti† (formerly Crocodylus pigotti)
- Brochuchus parvidens†
- Genus Euthecodon†
- Genus Rimasuchus†
- Rimasuchus lloydi† (formerly Crocodylus lloydi)
- Genus Osteolaemus
References
edit- ^ Brochu, Christopher A.; de Celis, Ane; Adams, Amanda J.; Drumheller, Stephanie K.; Nestler, Jennifer H.; Benefit, Brenda R.; Grossman, Aryeh; Kirera, Francis; Lehmann, Thomas; Liutkus-Pierce, Cynthia; Manthi, Fredrick K.; McCrossin, Monte L.; McNulty, Kieran P.; Nyaboke Juma, Rose (2022). "Giant dwarf crocodiles from the Miocene of Kenya and crocodylid faunal dynamics in the late Cenozoic of East Africa". The Anatomical Record. 305 (10): 2729–2765. doi:10.1002/ar.25005. ISSN 1932-8486. PMC 9541231. PMID 35674271.
- ^ Brochu, C. A.; Storrs, G. W. (2012). "A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity of Crocodylus in Africa". Journal of Vertebrate Paleontology. 32 (3): 587–602. Bibcode:2012JVPal..32..587B. doi:10.1080/02724634.2012.652324. S2CID 85103427.
- ^ a b Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
- ^ a b Eaton, Mitchell J.; Andrew Martin; John Thorbjarnarson; George Amato (March 2009). "Species-level diversification of African dwarf crocodiles (Genus Osteolaemus): A geographic and phylogenetic perspective". Molecular Phylogenetics and Evolution. 50 (3): 496–506. doi:10.1016/j.ympev.2008.11.009. PMID 19056500.
- ^ Michael S. Y. Lee; Adam M. Yates (27 June 2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil". Proceedings of the Royal Society B. 285 (1881). doi:10.1098/rspb.2018.1071. PMC 6030529. PMID 30051855.
- ^ Hekkala, E.; Gatesy, J.; Narechania, A.; Meredith, R.; Russello, M.; Aardema, M. L.; Jensen, E.; Montanari, S.; Brochu, C.; Norell, M.; Amato, G. (2021-04-27). "Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus". Communications Biology. 4 (1): 505. doi:10.1038/s42003-021-02017-0. ISSN 2399-3642. PMC 8079395. PMID 33907305.
- ^ a b Azarra, Beatrice; Boschian, Giovanni; Brochu, Christopher; Delfino, Massimo; Iurino, Dawid Adam; Kimambo, Jackson Stanley; Manzi, Giorgio; Masao, Fidelis T.; Menconero, Sofia; Njau, Jackson K; Cherin, Marco (2021). "A new cranium of Crocodylus anthropophagus from Olduvai Gorge, northern Tanzania". Rivista Italiana di Paleontologia e Stratigrafia (Research in Paleontology and Stratigraphy). 127 (2): 275–295. doi:10.13130/2039-4942/15771.