Biology:Notocaiman
| Notocaiman | |
|---|---|
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Superfamily: | |
| Family: | |
| Genus: | Notocaiman Rusconi, 1937
|
| Species | |
| |
Notocaiman is an extinct genus of alligatorid crocodylian. A fragmentary and poorly preserved left dentary found in the Peñas Coloradas Formation of Argentina that presumably dates back to the Paleocene epoch (Peligran-Riochican),[1] is all that is known from the genus.[2] The genus and its only species, N. stromeri, were found to be dubious and were synonymized with Eocaiman palaeocenicus in 2022.[3]
Etymology
Notocaiman, the genus name, comes from the Greek roots Noto- meaning “near” and caiman, after the South American alligatoroid.[4]
History and taxonomy
Notocaiman was first described by C. Rusconi in 1937 on the basis of a left mandible fragment containing 14 alveoli (PVL 752) that had been collected from the Middle Paleocene strata of the Las Violetas Formation in Escalante, Chubut Province, Argentina .[3][5][4] No additional fossils have been assigned to the genus or its type and sole species, N. stromeri.[3] In 1965, American paleontologist Wann Langston Jr. suggested that the species could be a relative of Eocaiman, another Paleocene alligatorid,[2] while Gasparani (1973) found the species to be dubious and an indeterminate Eusuchian.[6] Bona & Barrios (2015) kept the genus valid as an indeterminate alligatorid, but stated that it was possibly synonymous with Eocaiman.[5] However in 2022, another analysis by Bona and colleagues found the genus and its type species to be dubious and referred the type specimen to Eocaiman cf. E. palaeocenicus.[3]
Description
Notocaiman was characterized by Rusconi (1937) as a huge alligatorid with a robust mandible and robust 12th and 13th teeth on the dentary. Langston diagnosed the species by the relative size of these teeth compared to Eocaiman, which has a similar morphology but not as extreme as in Notocaiman.[2] Both Notocaiman and Eocaiman’s symphyses extend past the 5th mandibular tooth and both have anteriorly low mandibles that are less festooned than in other alligatorids.[7][5][2] Similarities between the remains of Notocaiman and comparable material from the alligatoroid Listrognathosuchus have been observed, but have not been taken as evidence for synonymy.[8]
All of these proposed diagnostic features are already found in Eocaiman, E. palaeocenicus specifically, making the taxon a nomen dubium.[3]
References
- ↑ Notocaiman at Fossilworks.org
- ↑ 2.0 2.1 2.2 2.3 Langston, W. (1965). Fossil crocodilians from Colombia and the Cenozoic history of the Crocodilia in South America. University of California Publications in Geological Sciences 52. University of California Press. pp. 1–152.
- ↑ 3.0 3.1 3.2 3.3 3.4 Bona, Paula; Barrios, Francisco; Ezcurra, Martín D.; Blanco, M. Victoria Fernandez (2022). "The Taxonomic Status of Notocaiman stromeri (Crocodylia, Alligatoroidea) and the Early Diversity of South American Caimanines". Ameghiniana 59 (3): 210–220. doi:10.5710/AMGH.27.02.2022.3470. ISSN 0002-7014. https://bioone.org/journals/ameghiniana/volume-59/issue-3/AMGH.27.02.2022.3470/The-Taxonomic-Status-of-Notocaiman-stromeri-Crocodylia-Alligatoroidea-and-the/10.5710/AMGH.27.02.2022.3470.full.
- ↑ 4.0 4.1 Rusconi, C. (1937). Nuevo aligatorino del Paleoceno argentino. Boletin Paleontologico de Buenos Aires, 8, 1-5.
- ↑ 5.0 5.1 5.2 Bona, P., & Barrios, F. (2015). The Alligatoroidea of Argentina: an update of its fossil record. Publicación Electrónica de la Asociación Paleontológica Argentina, 51.
- ↑ de Gasparini, Z. N. B., & Pascual, R. (1973). Revisión de los Crocodilia [Reptilia] fósiles del territorio argentino: Su evolución, sus relaciones filogenéticas, su clasificación y sus implicancias estratigráficas.
- ↑ BROCHU, CHRISTOPHER A. (2011-12-01). "Phylogenetic relationships of Necrosuchus ionensis Simpson, 1937 and the early history of caimanines". Zoological Journal of the Linnean Society 163 (suppl_1): S228–S256. doi:10.1111/j.1096-3642.2011.00716.x. ISSN 0024-4082. https://doi.org/10.1111/j.1096-3642.2011.00716.x.
- ↑ Brochu, C. A. (1997). "A review of "Leidyosuchus" (Crocodyliformes, Eusuchia) from the Cretaceous through Eocene of North America". Journal of Vertebrate Paleontology 17 (4): 679–697. doi:10.1080/02724634.1997.10011017.
Wikidata ☰ Q7063131 entry
 |
