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Added information referring to the teeth of Chenanisuchus and its subaqueous locomotion, with implications for its survival of the K-Pg extinction
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| taxon = Chenanisuchus
| taxon = Chenanisuchus
| authority = Jouve ''et al.'', [[2005 in paleontology|2005]]
| authority = Jouve ''et al.'', [[2005 in paleontology|2005]]
| type_species = {{extinct}}'''''Ch. lateroculi'''''
| type_species = {{extinct}}'''''Chenanisuchus lateroculi'''''
| type_species_authority = Jouve ''et al.'' 2005
| type_species_authority = Jouve ''et al.'' 2005
}}
}}
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The type species is ''C. lateroculi'' ("lateralis", lateral; "oculi", eyes), in reference to the laterally facing eyes.
The type species is ''C. lateroculi'' ("lateralis", lateral; "oculi", eyes), in reference to the laterally facing eyes.


Currently, ''Chenanisuchus'' is the most [[basal node|basal]] known dyrosaurid.<ref name=hastings>{{cite journal|author=Hastings, A.K.|author-link=Alexander K. Hastings|author2=Bloch, J.|author2-link=Jonathan Bloch|author3=Jaramillo, C.A.|author3-link=Carlos A. Jaramillo|name-list-style=amp|year=2011|title=A new longirostrine dyrosaurid (Crocodylomorpha, Mesoeucrocodylia) from the Paleocene of north-eastern Colombia: biogeographic and behavioural implications for new-world dyrosauridae|journal=Palaeontology|volume=54|issue=5|pages=1095–116|doi=10.1111/j.1475-4983.2011.01092.x|doi-access=free}}</ref>
Currently, ''Chenanisuchus'' is the most [[basal node|basal]] known dyrosaurid.<ref name=hastings>{{cite journal|author=Hastings, A.K.|author-link=Alexander K. Hastings|author2=Bloch, J.|author2-link=Jonathan Bloch|author3=Jaramillo, C.A.|author3-link=Carlos A. Jaramillo|name-list-style=amp|year=2011|title=A new longirostrine dyrosaurid (Crocodylomorpha, Mesoeucrocodylia) from the Paleocene of north-eastern Colombia: biogeographic and behavioural implications for new-world dyrosauridae|journal=Palaeontology|volume=54|issue=5|pages=1095–116|doi=10.1111/j.1475-4983.2011.01092.x|doi-access=}}</ref>


== Material ==
== Material ==
Two specimens of ''C. lateroculi'' – OCP DEK-GE 262 ([[holotype]], nearly complete skull with mandibular fragments) and OCP DEK-GE 61 (nearly complete skull) – come from the Sidi Chenane area in Morocco, which is Late Palaeocene (Thanetian) in age.<ref name=":0">Jouve ''et al.'', 2005.</ref> Fossils of ''Chenanisuchus'' were also found in [[Maastrichtian]] age strata in [[Mali]], showing that ''Chenanisuchus'' survived the [[Cretaceous–Paleogene extinction event]].<ref name=AMN08>{{Cite journal |author1=Hill, Robert V. |author2=McCartney, Jacob A. |author3=Roberts, Eric |author4=Bouaré, Mohamed |author5=Sissoko, Famory |author6=O'Leary, Maureen A. |year=2008 |title=Dyrosaurid (Crocodyliformes: Mesoeucrocodylia) Fossils from the Upper Cretaceous and Paleogene of Mali: Implications for Phylogeny and Survivorship across the K/T Boundary |journal=American Museum Novitates |issue=3631 |pages=1–19 |doi=10.1206/598.1|hdl=2246/5940 |s2cid=56118152 |url=https://www.biodiversitylibrary.org/itempdf/280918 }}</ref>
Two specimens of ''C. lateroculi'' – OCP DEK-GE 262 ([[holotype]], nearly complete skull with mandibular fragments) and OCP DEK-GE 61 (nearly complete skull) – come from the Sidi Chenane area in Morocco, which is Late Palaeocene ([[Thanetian]]) in age.<ref name=":0">Jouve ''et al.'', 2005.</ref> Fossils of ''Chenanisuchus'' were also found in [[Maastrichtian]] age strata in [[Mali]], showing that ''Chenanisuchus'' survived the [[Cretaceous–Paleogene extinction event]].<ref name=AMN08>{{Cite journal |author1=Hill, Robert V. |author2=McCartney, Jacob A. |author3=Roberts, Eric |author4=Bouaré, Mohamed |author5=Sissoko, Famory |author6=O'Leary, Maureen A. |year=2008 |title=Dyrosaurid (Crocodyliformes: Mesoeucrocodylia) Fossils from the Upper Cretaceous and Paleogene of Mali: Implications for Phylogeny and Survivorship across the K/T Boundary |journal=American Museum Novitates |issue=3631 |pages=1–19 |doi=10.1206/598.1|hdl=2246/5940 |s2cid=56118152 |url=https://www.biodiversitylibrary.org/itempdf/280918 }}</ref>


== Systematics ==
== Systematics ==
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== Palaeobiology ==
== Palaeobiology ==
''Chenanisuchus lateroculi'' has an estimated adult length between 4 and 4.5 meters, based on the 60 centimeter long skull. It has the shortest snout relative to the dorsal skull length among all dyrosaurids, but its snout is thicker and its skull less slender than in dyrosaurids such as ''Sokotosuchus.'' There appear to be 4 teeth on each [[premaxilla]], with an estimated 13 on each [[maxilla]]. The teeth on the maxillae and [[dentaries]] are short and robust, but sharp.<ref name=":0" />
''Chenanisuchus lateroculi'' has an estimated adult length between 4 and 4.5 meters, based on the 60 centimeter long skull. It has the shortest snout relative to the dorsal skull length among all dyrosaurids, but its snout is thicker and its skull less slender than in dyrosaurids such as ''[[Sokotosuchus]].'' There appear to be 4 teeth on each [[premaxilla]], with an estimated 13 on each [[maxilla]]. The teeth on the maxillae and [[dentaries]] are short and robust, but sharp.<ref name=":0" />


Studies into the inner ear morphology of Malian dyrosaurids suggest that they were adapted for walking on the sea floor as opposed to swimming, a hypothesis supported by the apparent lack of adaptations for swimming seen in other [[Marine biology|marine]] [[Crocodyliformes|crocodyliforms]] (e.g. [[Metriorhynchidae]]) such as paddlelike fins.<ref>{{Cite journal |last=Georgi |first=J. |date=2006 |title=Dyrosaurid inner ear morphology as evidence for locomotor behavior |journal=Journal of Vertebrate Paleontology}}</ref> This way of subaqueous locomotion is suggested to have contributed to the survival of dyrosaurids such as ''Chenanisuchus'' across the [[K-Pg boundary]].<ref name="AMN08" />
Studies of the [[inner ear]] morphology of Malian dyrosaurids suggest that they were adapted for walking on the sea floor as opposed to swimming, a hypothesis supported by the apparent lack of adaptations for swimming seen in other [[Marine biology|marine]] [[Crocodyliformes|crocodyliforms]] (e.g. [[Metriorhynchidae]]) such as paddlelike fins.<ref>{{Cite journal |last=Georgi |first=J. |date=2006 |title=Dyrosaurid inner ear morphology as evidence for locomotor behavior |journal=Journal of Vertebrate Paleontology |volume=26 |issue= |pages=66A}}</ref> This mode of subaqueous locomotion is suggested to have contributed to the survival of dyrosaurids such as ''Chenanisuchus'' across the [[K-Pg boundary]].<ref name="AMN08" />


== References ==
== References ==
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[[Category:Prehistoric marine crocodylomorphs]]
[[Category:Prehistoric marine crocodylomorphs]]
[[Category:Late Cretaceous crocodylomorphs of Africa]]
[[Category:Late Cretaceous crocodylomorphs of Africa]]
[[Category:Late Cretaceous reptiles of Africa]]
[[Category:Paleocene reptiles of Africa]]
[[Category:Paleogene reptiles of Africa]]
[[Category:Paleocene crocodylomorphs]]
[[Category:Paleocene crocodylomorphs]]
[[Category:Fossil taxa described in 2005]]
[[Category:Fossil taxa described in 2005]]
[[Category:Fossils of Mali]]




{{paleo-archosaur-stub}}
{{paleo-archosaur-stub}}
[[Category:Fossils of Mali]]

Latest revision as of 04:52, 16 February 2024

Chenanisuchus
Life restoration of Chenanisuchus lateroculi
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Pseudosuchia
Clade: Crocodylomorpha
Clade: Crocodyliformes
Family: Dyrosauridae
Genus: Chenanisuchus
Jouve et al., 2005
Type species
Chenanisuchus lateroculi
Jouve et al. 2005

Chenanisuchus ("Chenane crocodile") is a genus of dyrosaurid crocodyliform from the Late Cretaceous of Mali and the Late Palaeocene of Sidi Chenane in Morocco. It was described in 2005, after expeditions uncovered it in 2000.

The type species is C. lateroculi ("lateralis", lateral; "oculi", eyes), in reference to the laterally facing eyes.

Currently, Chenanisuchus is the most basal known dyrosaurid.[1]

Material

[edit]

Two specimens of C. lateroculi – OCP DEK-GE 262 (holotype, nearly complete skull with mandibular fragments) and OCP DEK-GE 61 (nearly complete skull) – come from the Sidi Chenane area in Morocco, which is Late Palaeocene (Thanetian) in age.[2] Fossils of Chenanisuchus were also found in Maastrichtian age strata in Mali, showing that Chenanisuchus survived the Cretaceous–Paleogene extinction event.[3]

Systematics

[edit]

Chenanisuchus lateroculi is referred to Dyrosauridae by Jouve et al. (2005), based on three morphological characters:

  • Presence of occipital tuberosities
  • Presence of an anterolateral postorbital process
  • Large participation of the quadratojugal and surangular to the jaw joint

Palaeobiology

[edit]

Chenanisuchus lateroculi has an estimated adult length between 4 and 4.5 meters, based on the 60 centimeter long skull. It has the shortest snout relative to the dorsal skull length among all dyrosaurids, but its snout is thicker and its skull less slender than in dyrosaurids such as Sokotosuchus. There appear to be 4 teeth on each premaxilla, with an estimated 13 on each maxilla. The teeth on the maxillae and dentaries are short and robust, but sharp.[2]

Studies of the inner ear morphology of Malian dyrosaurids suggest that they were adapted for walking on the sea floor as opposed to swimming, a hypothesis supported by the apparent lack of adaptations for swimming seen in other marine crocodyliforms (e.g. Metriorhynchidae) such as paddlelike fins.[4] This mode of subaqueous locomotion is suggested to have contributed to the survival of dyrosaurids such as Chenanisuchus across the K-Pg boundary.[3]

References

[edit]
  1. ^ Hastings, A.K.; Bloch, J. & Jaramillo, C.A. (2011). "A new longirostrine dyrosaurid (Crocodylomorpha, Mesoeucrocodylia) from the Paleocene of north-eastern Colombia: biogeographic and behavioural implications for new-world dyrosauridae". Palaeontology. 54 (5): 1095–116. doi:10.1111/j.1475-4983.2011.01092.x.
  2. ^ a b Jouve et al., 2005.
  3. ^ a b Hill, Robert V.; McCartney, Jacob A.; Roberts, Eric; Bouaré, Mohamed; Sissoko, Famory; O'Leary, Maureen A. (2008). "Dyrosaurid (Crocodyliformes: Mesoeucrocodylia) Fossils from the Upper Cretaceous and Paleogene of Mali: Implications for Phylogeny and Survivorship across the K/T Boundary". American Museum Novitates (3631): 1–19. doi:10.1206/598.1. hdl:2246/5940. S2CID 56118152.
  4. ^ Georgi, J. (2006). "Dyrosaurid inner ear morphology as evidence for locomotor behavior". Journal of Vertebrate Paleontology. 26: 66A.

Bibliography

[edit]
  • Jouve, S., Bouya, B. & Amaghzaz, M., (2005). A short-snouted dyrosaurid (Crocodyliformes, Mesoeucrocodylia) from the Palaeocene of Marocco. Palaeontology 48 (2): 359–369. doi:10.1111/j.1475-4983.2005.00442.x