Obaichthyidae

Obaichthyidae
Temporal range: Aptian–Cenomanian
Fossil of Obaichthys decoratus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Clade: Ginglymodi
Order: Lepisosteiformes
Superfamily: Lepisosteoidea
Family: †Obaichthyidae
Grande, 2010
Genera

Obaichthyidae is an extinct family of ginglymodian ray-finned fish that lived in what is now Africa, South America, and southern Europe during the Cretaceous period (Aptian–Cenomanian ages). They were close relatives of the modern gars of the family Lepisosteidae, with the two groups making up the superfamily Lepisosteoidea.[1]

They closely resembled gars, with one difference being their spiny scales, leading to the common name spiny gars.[2][3] They also differ from extant gars in their highly specialized jaws, with a mobile maxilla & a reduced lower jaw leading to a prominent overbite, teeth concentrated at the tip, and a very small gape, indicating that they likely fed on small invertebrates, in contrast to all lepisosteids which are adapted to feed on other vertebrates.[4]

Like modern gars, they appear to have preferred freshwater & brackish environments but were tolerant of marine conditions, allowing them to disperse across oceanic habitats. Both confirmed genera have respective species in both South America and Africa, with the African Obaichthys species also being known from southern Europe.[5]

The family was erected in 2010 by Lance Grande to include the genera Dentilepisosteus and Obaichthys.[2][6] In 2012, it was defined as a stem-based taxon containing all taxa more closely related to Obaichthys than to the genera Lepisosteus, Pliodetes or Lepidotes.[1] Afrocascudo, initially described as the earliest known armored catfish, might represent a juvenile obaichthyid, possibly a junior synonym of Obaichthys,[7] though this has been disputed based on the complete ossification of the bones indicating full maturity and the absence of important holostean characters.[8]

  1. ^ a b Cite error: The named reference López2012 was invoked but never defined (see the help page).
  2. ^ a b Grande, Lance (2010). "An Empirical Synthetic Pattern Study of Gars (lepisosteiformes) and Closely Related Species, Based Mostly on Skeletal Anatomy. the Resurrection of Holostei". Copeia. 2010 (2A): iii–871. ISSN 0045-8511. JSTOR 20787269.
  3. ^ Cooper, Samuel L. A.; Gunn, James; Brito, Paulo M.; Zouhri, Samir; Martill, David M. (2023-11-01). "A new fully marine, short-snouted lepisosteid gar from the Upper Cretaceous (Turonian) of North Africa". Cretaceous Research. 151: 105650. Bibcode:2023CrRes.15105650C. doi:10.1016/j.cretres.2023.105650. ISSN 0195-6671. S2CID 259520870.
  4. ^ Cavin, Lionel; Boudad, Larbi; Tong, Haiyan; Läng, Emilie; Tabouelle, Jérôme; Vullo, Romain (2015-05-27). "Taxonomic Composition and Trophic Structure of the Continental Bony Fish Assemblage from the Early Late Cretaceous of Southeastern Morocco". PLOS ONE. 10 (5): e0125786. Bibcode:2015PLoSO..1025786C. doi:10.1371/journal.pone.0125786. ISSN 1932-6203. PMC 4446216. PMID 26018561.
  5. ^ Pimentel, Ricardo; Barroso-Barcenilla, Fernando; Berrocal-Casero, Mélani; Callapez, Pedro Miguel; Ozkaya de Juanas, Senay; dos Santos, Vanda F. (2023). "On the Occurrence of the Gar Obaichthys africanus Grande in the Cretaceous of Portugal: Palaeoecological and Palaeobiogeographical Implications". Geosciences. 13 (12): 372. Bibcode:2023Geosc..13..372P. doi:10.3390/geosciences13120372. ISSN 2076-3263.
  6. ^ Cite error: The named reference Brito2016 was invoked but never defined (see the help page).
  7. ^ Britz, R.; Pinion, Amanda K.; Kubicek, Kole M.; Conway, Kevin W. (2024). "Comment on "A Saharan fossil and the dawn of Neotropical armoured catfishes in Gondwana" by Brito et al". Gondwana Research. 133: 267–269. Bibcode:2024GondR.133..267B. doi:10.1016/j.gr.2024.06.014.
  8. ^ Brito, Paulo M.; Dutheil, Didier B.; Keith, Philippe; Carnevale, Giorgio; Meunier, François J.; Khalloufi, Bouziane; Gueriau, Pierre (2024). "A reply to a comment on Brito et al., 2024, A Saharan fossil and the dawn of the Neotropical armoured catfishes in Gondwana by Britz, Pinion, Kubicek and Conway". Gondwana Research. doi:10.1016/j.gr.2024.06.013.