Ilchunaia

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Ilchunaia
Temporal range: Late Eocene (Divisaderan-Tinguirirican)
~37.2–33.9  Ma
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Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Suborder: Notosuchia
Clade: Sebecosuchia
Clade: Sebecia
Family: Sebecidae
Genus: Ilchunaia
Rusconi, 1946
Type species
Ilchunaia parva
Rusconi, 1946

Ilchunaia is an extinct genus of sebecid mesoeucrocodylian. Fossils have been found from the Divisadero Largo Formation of Argentina dating back to the Late Eocene, [1] [2] [3] and a locality in Mendoza, Argentina dating back to the Oligocene. [4] [5] Little material is known from the genus, with only the anterior portion of the skull being present to study (the holotype has since been lost). [6] [7]

Contents

Taxonomy

The placement of Ilchunaia within Sebecosuchidae has been questioned in the past, and many recent phylogenetic analyses have shown the family to be entirely paraphyletic, with members most likely being basal sebecosuchians ancestral to the baurusuchids. [8] [9] [10] [11]

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Baurusuchidae Extinct family of reptiles

Baurusuchidae is a Gondwanan family of mesoeucrocodylians that lived during the Late Cretaceous. It is a group of terrestrial hypercarnivorous crocodilians from South America and possibly Pakistan. Baurusuchidae has been, in accordance with the PhyloCode, officially defined as the least inclusive clade containing Cynodontosuchus rothi, Pissarrachampsa sera, and Baurusuchus pachecoi. Baurusuchids have been placed in the suborder Baurusuchia, and two subfamilies have been proposed: Baurusuchinae and Pissarrachampsinae.

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<i>Bretesuchus</i> Extinct genus of reptiles

Bretesuchus is an extinct genus of sebecosuchian mesoeucrocodylian within the family Sebecidae known from northwestern Argentina. It was a large apex predator.

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<i>Sebecus</i> Extinct genus of reptiles

Sebecus is an extinct genus of sebecid crocodylomorph from Eocene of South America. Fossils have been found in among others Patagonia. Like other sebecosuchians, it was entirely terrestrial and carnivorous. The genus is currently represented by two species, the type S. icaeorhinus and S. ayrampu. Several other species have been referred to Sebecus, but were later reclassified as their own genera.

Sebecosuchia is an extinct group of mesoeucrocodylian crocodyliforms that includes the families Sebecidae and Baurusuchidae. The group was long thought to have first appeared in the Late Cretaceous with the baurusuchids and become extinct in the Miocene with the last sebecids, but Razanandrongobe pushes the origin of Sebecosuchia to the Middle Jurassic. Fossils have been found primarily from South America but have also been found in Europe, North Africa, Madagascar, and the Indian subcontinent.

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References

  1. Ilchunaia at Fossilworks.org
  2. Paolillo, Alfredo; and Linares, Omar J. (2007). Nuevos cocodrilos Sebecosuchia del Cenozoico Suramericano (Mesosuchia: Crocodylia). Paleobiologia Neotropical3: 1–25.
  3. Turner, A. H. and Calvo, J. O. (2005). A new sebecosuchian crocodyliform from the Late Cretaceous of Patagonia. Journal of Vertebrate Paleontology25(1):87–98.
  4. Rusconi, C. (1946). Ave y reptil oligocenos de Mendoza. Bolletín Paleontológico (Buenos Aires)21:1–3.
  5. Langston, W. J. (1956). The Sebecosuchia: cosmopolitan crocodilians? American Journal of Science254:605–614.
  6. Gasparini, Z., Fernández, M. and Powell, J. (1993). New Tertiary Sebecosuchians (Crocodylomorpha) from South America: Phylogenetic Implications. Hististorical Biology7:1-19.
  7. Gasparini, Z. (1972). Los Sebecosuchia (Crocodilia) del territorio argentino. Consideraciones sobre su “status” taxonómico. Ameghiniana9(1): 23-34.
  8. Busbey III, A. B. (1986). New material of Sebecus cf. huilensis (Crocodilia: Sebecosuchia) from the Miocene La Venta Formation of Colombia. Journal of Vertebrate Paleontology6(1):20-27.
  9. Gasparini, Z., Fernández, M. and Powell, J. (1993). New Tertiary Sebecosuchians (Crocodylomorpha) from South America: Phylogenetic Implications. Hististorical Biology7:1-19.
  10. Ortega, F., Buscalioni, A. D. and Gasparini, Z. (1996). Reinterpretation and new denomination of Atacisaurus crassiporatus (Middle Eocene; Issel, France) as cf. Iberosuchus (Crocodylomorpha, Metasuchia). Geobios29:353–364.
  11. Ortega, F., Gasparini, Z., Buscalioni, A. D., and Calvo, J. O. (2000). A new species of Araripesuchus (Crocodylomorpha, Mesoeucrocodylia) from the Lower Cretaceous of Patagonia (Argentina). Journal of Vertebrate Paleontology20:57–76.