Cuneatus

Last updated

Cuneatus
Temporal range: Late Paleocene–Early Eocene
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Clade: Ginglymodi
Order: Lepisosteiformes
Family: Lepisosteidae
Tribe: Cuneatini
Genus: Cuneatus
Grande, 2010
Species
  • Cuneatus cuneatus(Cope, 1878)
  • Cuneatus maximusBrownstein, 2022
  • Cuneatus wileyiGrande, 2010
Synonyms
  • Lepisosteus cuneatusCope, 1878

Cuneatus is an extinct genus of gar that inhabited western North America during the early Paleogene. As the genus name suggests, they are distinguishable from modern gar by their cuneate (wedge-shaped) heads, with a significantly shortened snout. [1] Three species are known: C. cuneatus, C. maximus, and C. wileyi.

Taxonomy

Along with Masillosteus , they are thought to belong to the Cuneatini, a now-extinct tribe of short-snouted gar. The tribe and both genera are thought to have originated in the Cretaceous, despite being only known from Paleogene fossils. Species in Cuneatus are known to have coexisted with species belonging to both extant gar genera (Atractosteus and Lepisosteus) in known localities. [2]

The type species of the genus was described as " Lepisosteus " cuneatus by Edward Drinker Cope from the Green River Formation of Utah. A 2010 study by Lance Grande found it to be morphologically highly divergent from any of the extant genera, and thus classified it in its own genus Cuneatus, in addition to describing a second species of Cuneatus (C. wileyi) from the Green River Formation. [1] Both species are common in mass death assemblages from the "Lake Uinta" division of the formation. [3] [4]

The largest species in the genus, Cuneatus maximus, was described by Brownstein (2022) from the Willwood Formation of Wyoming, from which it is the first known fossil fish. Its distinct morphology and geographic separation from the other two Cuneatus species indicates it to be the basal species of the genus. [3]

Related Research Articles

<span class="mw-page-title-main">Gar</span> Family of fishes

Gars are an ancient group of ray-finned fish in the family Lepisosteidae. They comprise seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine waters of eastern North America, Central America and Cuba in the Caribbean, though extinct members of the family were more widespread. They are the only surviving members of the Ginglymodi, a clade of fish which first appeared during the Triassic, over 240 million years ago, and are one of only two surviving groups of holosteian fish, alongside the bowfins, which have a similar distribution.

Lepisosteus is a genus of gars in the family Lepisosteidae.

<span class="mw-page-title-main">Green River Formation</span> Geologic formation in the United States

The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.

<span class="mw-page-title-main">Longnose gar</span> Species of fish

The longnose gar, also known as longnose garpike or billy gar, is a ray-finned fish in the family Lepisosteidae. The genus may have been present in North America for about 100 million years. References are made to gars being a primitive group of bony fish because they have retained some primitive features, such as a spiral valve intestine, but they are not primitive in the sense of not being fully developed.

<i>Knightia</i> Extinct genus of fishes

Knightia is an extinct genus of clupeid bony fish that lived in the freshwater lakes and rivers of North America and Asia during the Eocene epoch. The genus was erected by David Starr Jordan in 1907, in honor of the late University of Wyoming professor Wilbur Clinton Knight, "an indefatigable student of the paleontology of the Rocky Mountains." It is the official state fossil of Wyoming, and the most commonly excavated fossil fish in the world.

<i>Chlamydoselachus</i> Genus of sharks

Chlamydoselachus is a genus of sharks and the sole extant member of the family Chlamydoselachidae, in the order Hexanchiformes. It contains two extant and four extinct species. The most widely known species still surviving is the frilled shark. It is known as a living fossil, along with Chlamydoselachus africana, also known as the southern African frilled shark, which is only found along coastal areas of South Africa. The only two extant species of this genus are deep-sea creatures which are typically weakened in areas closer to the surface. While the two extant species are similar in external appearance, they differ internally.

<span class="mw-page-title-main">Holostei</span> Group of bony fish

Holostei is a group of ray-finned bony fish. It is divided into two major clades, the Halecomorphi, represented by the single living genus, Amia with two species, the bowfins, as well as the Ginglymodi, the sole living representatives being the gars (Lepisosteidae), represented by seven living species in two genera. The earliest members of the clade, which are putative "semionotiforms" such as Acentrophorus and Archaeolepidotus, are known from the Middle to Late Permian and are among the earliest known neopterygians.

<i>Titanoboa</i> Extinct genus of snakes

Titanoboa is an extinct genus of giant boid snake that lived during the middle and late Paleocene. Titanoboa was first discovered in the early 2000s by the Smithsonian Tropical Research Institute who, along with students from the University of Florida, recovered 186 fossils of Titanoboa from La Guajira in northeastern Colombia. It was named and described in 2009 as Titanoboa cerrejonensis, the largest snake ever found at that time. It was originally known only from thoracic vertebrae and ribs, but later expeditions collected parts of the skull and teeth. Titanoboa is in the subfamily Boinae, being most closely related to other extant boines from Madagascar and the Pacific.

<i>Atractosteus</i> Genus of fishes

Atractosteus is a genus of gars in the family Lepisosteidae, with three species. The genus first appeared in the Campanian in the Late Cretaceous.

<i>Gyaclavator</i> Extinct genus of true bugs

Gyaclavator is an extinct genus of lace bug in the family Tingidae known from a fossil found in North America. The genus contains a single species, Gyaclavator kohlsi.

<i>Enhydriodon</i> Extinct genus of carnivorans

Enhydriodon is an extinct genus of mustelids known from Africa, Pakistan and India that lived from the late Miocene to the early Pleistocene. It contains nine confirmed species, two debated species, and at least a few other undescribed species from Africa. The genus belongs to the tribe Enhydriodontini in the otter subfamily Lutrinae. Enhydriodon means "otter tooth" in Ancient Greek and is a reference to its dentition rather than to the Enhydra genus, which includes the modern sea otter and its two prehistoric relatives.

<i>Amia</i> (fish) Genus of ray-finned fishes

Amia, commonly called bowfin, is a genus of ray-finned fish related to gars in the infraclass Holostei. They are regarded as taxonomic relicts, being the sole surviving species of the order Amiiformes and clade Halecomorphi, which dates from the Triassic to the Eocene, persisting to the present. There are two living species in Amia, Amia calva and Amia ocellicauda, and a number of extinct species which have been described from the fossil record.

<span class="mw-page-title-main">Lance Grande</span>

Roger Lansing Grande, more commonly known as Lance Grande, is an evolutionary biologist and curatorial scientist. His research and work is focused on Paleontology, Ichthyology, Systematics and Evolution. He is well known for his work on the paleontology of the Green River Formation and for his detailed monographs on the comparative anatomy and evolution of ray-finned fishes. He has also published books on broader issues, engaging larger audiences on the importance of the natural and the social sciences.

<span class="mw-page-title-main">Obaichthyidae</span> Extinct family of ray-finned fishes

Obaichthyidae is an extinct family of ginglymodian ray-finned fish that lived in what is now Africa and South America during the Cretaceous period. It was erected in 2010 by Lance Grande to include the genera Dentilepisosteus and Obaichthys. 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.

<i>Atractosteus grandei</i> Extinct species of fish

Atractosteus grandei is an extinct species of gar in the family Lepisosteidae. Remains have been found in Lower Paleogene sediments from North Dakota. A. grandei belonged to the genus Atractosteus which includes modern day species of gars such as the giant alligator gar and the tropical gar. It is named after paleontologist and ichthyologist Lance Grande.

<i>Masillosteus</i> Genus of fishes

Masillosteus is an extinct genus of gar that inhabited western North America and Europe during the Eocene. It is known from two species, each from a famous freshwater lagerstätte: M. kelleri from the Messel pit in the Messel Formation of Germany, and M. janeae from Fossil Butte in the Green River Formation of Wyoming. They are known from only a few specimens from both localities, and may have not been permanent inhabitants of the fossil lakes where they were preserved.

<i>Cyrilavis</i> Extinct genus of birds

Cyrilavis is an extinct genus of halcyornithid bird from the Early Eocene Fossil Butte Member of the Green River Formation, United States. The genus contains two species, Cyrilavis olsoni and Cyrilavis colburnorum.

Oniichthys is an extinct genus of gar in the family Lepisosteidae. It contains a single species, O. falipoui, known from the Late Cretaceous (Cenomanian) of Morocco.

Herreraichthys is an extinct genus of gar from the Late Cretaceous of Mexico. It contains a single species, H. coahuilaensis. The genus name honors the famous Mexican scientist Alfonso L. Herrera.

<i>Grandemarinus</i> Extinct genus of gar

Grandemarinus is an extinct genus of gar from the Late Cretaceous of Morocco. It contains a single species, G. gherisensis. The genus name honors evolutionary biologist Lance Grande and references the species' apparent marine nature, while the specific epithet references Oued Gheris, a wadi near the type locality.

References

  1. 1 2 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.
  2. Brownstein, Chase Doran; Yang, Liandong; Friedman, Matt; Near, Thomas J. (20 December 2022). "Phylogenomics of the Ancient and Species-Depauperate Gars Tracks 150 Million Years of Continental Fragmentation in the Northern Hemisphere". Systematic Biology. 72 (1): 213–227. Retrieved 5 June 2023.
  3. 1 2 "Unappreciated Cenozoic ecomorphological diversification of stem gars revealed by a new large species – Acta Palaeontologica Polonica". www.app.pan.pl. Retrieved 20 June 2023.
  4. Dayvault, Richard D. (1995). "Note on Lepisosteus Cuneatus, A Gar from Lake Uinta". The Green River Formation in Piceance Creek and Eastern Uinta Basins.