Nhanulepisosteus (nhanu, Mixteca for "old" + Lepisosteus) is an extinct genus of gar known from the Late Jurassic of Oaxaca, Mexico. It contains a single species, N. mexicanus. It is the oldest species of true gar known from fossil remains.[1][2][3]

Nhanulepisosteus
Temporal range: Late Jurassic (Kimmeridgian), 157 Ma
Fossil neurocranium
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Clade: Ginglymodi
Order: Lepisosteiformes
Family: Lepisosteidae
Genus: Nhanulepisosteus
Brito, Alvarado-Ortega & Meunier, 2017
Species:
N. mexicanus
Binomial name
Nhanulepisosteus mexicanus
Brito, Alvarado-Ortega & Meunier, 2017

Nhanulepisosteus is known from disarticulated cranial remains and ganoid scales from the Kimmeridgian-aged Llano Yosobé deposits of the Sabinal Formation. Although retaining some traits of basal Ginglymodi, it has certain derived features such as jaw structure that more closely resemble modern gar, indicating that gar are a highly morphologically conservative group.[2]

Nhanulepisosteus inhabited a fully marine environment, contrasting with modern gar that are largely freshwater taxa, with only occasional sightings in marine environments. This indicates that gar may have originally been marine fish before invading freshwater environments prior to the Early Cretaceous.[2]

References

edit
  1. ^ "Fossilworks: Nhanulepisosteus". www.fossilworks.org. Retrieved 26 May 2023.
  2. ^ a b c Brito, Paulo M.; Alvarado-Ortega, Jésus; Meunier, François J. (19 December 2017). "Earliest known lepisosteoid extends the range of anatomically modern gars to the Late Jurassic". Scientific Reports. 7 (1): 17830. Bibcode:2017NatSR...717830B. doi:10.1038/s41598-017-17984-w. ISSN 2045-2322. PMC 5736718. PMID 29259200.
  3. ^ "Gar | Fish & Facts | Britannica". www.britannica.com. Retrieved 26 May 2023.