Anconastes

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Anconastes
Temporal range: Late Carboniferous
Anconastes.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Order: Temnospondyli
Family: Trematopidae
Genus: Anconastes
Berman et al., 1987
Species
  • A. vesperusBerman et al., 1987 (type)

Anconastes is an extinct genus of dissorophoid temnospondyl within the family Trematopidae. It is known from two specimens from the Late Carboniferous Cutler Formation of north-central New Mexico in the southwestern United States. [1] The genus name derives from two Greek roots, ankos ("mountain glen or valley") and nastes ("inhabitant"), which refers to the type locality of El Cobre Canyon where the specimens were found. The species name derives from the Latin word vesperus ("western"). The more complete specimen, the holotype, is a partial skull with articulated mandibles and a substantial amount of the postcranial skeleton. The less complete specimen, the paratype, consists only of the right margin of the skull with an articulated mandible.

Contents

Anatomy

When originally described, only three other trematopid taxa were recognized: Acheloma, Actiobates , and " Trematops " (now a synonym of Acheloma); Ecolsonia , which is now considered a trematopid by most workers, had recently been re-described as a dissorophid on the basis of new material. [2] Berman et al. suggested two autapomorphies: (1) an internal naris that is half as wide as it is long; and (2) a dense covering of non-overlapping scales or osteoderms in the dorsal trunk region. They further differentiated Anconastes from Acheloma and "Trematops" by several features: (1) large orbit with a width equal to 1/3 the midline length of the skull; (2) a short suborbital bar with a maxilla entering the orbital margin; (3) pointed snout without prominent dorsomedial expansion of the postparietals; (4) nasals, frontals, and parietals of subequal length; (5) parietals approximately three times the length of the postparietals; (6) frontals not extending beyond the anterior margin of the orbit; (7) large interpterygoid vacuities; (8) an open basicranial joint; and (9) absence of an internarial opening or bone. They differentiated Anconastes from Actiobates by the presence of a quadratojugal contributing substantially to the ventral margin of the otic notch.

More recent review work has refined the diagnostic features to a handful of the original features proposed by Berman et al. with the study of additional trematopid material and the description of new taxa. [3]

Relationships

Anconastes is an uncontroversial trematopid and is most often recovered as the sister taxon to Tambachia from the early Permian Bromacker Quarry in Germany. [4] [5] Below is the topology from Polley & Reisz (2011): [6]

Sclerocephalus haeuseri

Micromelerpeton credneri

Micropholis stowi

Eoscopus lockardi

  Olsoniformes  

Cacops morrisi

  Trematopidae  

Phonerpeton pricei

  Acheloma  

Acheloma cumminsi

Acheloma dunni

Actiobates peabodyi

Ecolsonia cutlerensis

Anconastes vesperus

Tambachia trogallas

Related Research Articles

<i>Cacops</i> Extinct genus of amphibians

Cacops, is a genus of dissorophid temnospondylsfrom the Kungurian stage of the early Permian of the United States. Cacops is one of the few olsoniforms whose ontogeny is known. Cacops fossils were almost exclusively known from the Cacops Bone Bed of the Lower Permian Arroyo Formation of Texas for much of the 20th century. New material collected from the Dolese Brothers Quarry, near Richards Spur, Oklahoma in the past few decades has been recovered, painting a clearer picture of what the animal looked and acted like.

Dissorophidae Extinct family of amphibians

Dissorophidae is an extinct family of medium-sized, temnospondyl amphibians that flourished during the late Carboniferous and early Permian periods. The clade is known almost exclusively from North America.

<i>Seymouria</i> Extinct genus of reptile-like amphibians

Seymouria is an extinct genus of Seymouriamorph from the Early Permian of North America and Europe. Although they were amphibians, Seymouria were well-adapted to life on land, with many reptilian features—so many, in fact, that Seymouria was first thought to be a primitive reptile. It is primarily known from two species, Seymouria baylorensis and Seymouria sanjuanensis. The type species, S. baylorensis, is more robust and specialized, though its fossils have only been found in Texas. On the other hand, Seymouria sanjuanensis is more abundant and widespread. This smaller species is known from multiple well-preserved fossils, including a block of six skeletons found in the Cutler Formation of New Mexico, and a pair of fully grown skeletons from the Tambach Formation of Germany, which were fossilized lying next to each other.

<i>Limnoscelis</i> Genus of diadectomorphs

Limnoscelis was a genus of large diadectomorph tetrapods from the Late Carboniferous of western North America. It includes two species: the type species Limnoscelis paludis from New Mexico, and Limnoscelis dynatis from Colorado, both of which are thought to have lived concurrently. No specimens of Limnoscelis are known from outside of North America. Limnoscelis was carnivorous, and likely semiaquatic, though it may have spent a significant portion of its life on land. Limnoscelis had a combination of derived amphibian and primitive reptilian features, and its placement relative to Amniota has significant implications regarding the origins of the first amniotes.

<i>Acheloma</i> Extinct genus of amphibians

Acheloma is an extinct genus of temnospondyl that lived during the Early Permian. The type species is A. cumminsi.

Trematopidae Extinct family of amphibians

Trematopidae is a family of dissorophoid temnospondyl spanning the late Carboniferous to the early Permian. Together with Dissorophidae, the family forms Olsoniformes, a clade comprising the medium-large terrestrial dissorophoids. Trematopids are known from numerous localities in North America, primarily in New Mexico, Oklahoma, and Texas, and from the Bromacker quarry in Germany.

Actiobates is an extinct genus of trematopid temnospondyl that lived during the Late Carboniferous. It is known from the Garnett Quarry in Kansas.

<i>Ecolsonia</i> Extinct genus of amphibians

Ecolsonia is an extinct genus of trematopid temnospondyl. Its phylogenetic position within Olsoniformes has been historically debated, but it is presently considered to be a trematopid.

<i>Dissorophus</i> Extinct genus of amphibians

Dissorophus (DI-soh-ROH-fus) is an extinct genus of temnospondyl amphibian that lived during the Early Permian Period about 273 million years ago. Its fossils have been found in Texas and in Oklahoma in North America. Its heavy armor and robust build indicate Dissorophus was active on land, similar to other members of the clade Dissorophidae that are known from the Late Carboniferous to the Early Permian periods. Dissorphus is distinguished by its small body size, disproportionately large head and short trunk.

<i>Phonerpeton</i> Extinct genus of amphibians

Phonerpeton is an extinct genus of dissorophoid temnospondyl within the family Trematopidae that is known from the early Permian of Texas.

<i>Fedexia</i> Extinct genus of amphibians

Fedexia is an extinct genus of carnivorous temnospondyl within the family Trematopidae. It lived 300 million years ago during the late Carboniferous period. It is estimated to have been 2 feet (0.61 m) long, and likely resembled a salamander. Fedexia is known from a single skull found in Moon Township, Pennsylvania. It is named after the shipping service FedEx, which owned the land where the holotype specimen was first found.

<i>Tambachia</i> Extinct genus of amphibians

Tambachia is an extinct genus of dissorophoid temnospondyl within the family Trematopidae. It is known from the Early Permian Tambach Formation near the town of Tambach-Dietharz in Thuringia, Germany. Tambachia is the first trematopid to have been discovered outside the United States.

Pasawioops is an extinct genus of early Permian dissorophoid temnospondyl within the clade Amphibamiformes.

<i>Rubeostratilia</i> Extinct genus of amphibians

Rubeostratilia is an extinct genus of amphibamiform temnospondyl from the early Permian of Texas. It is known from a single skull. This genus was named by Hélène Bourget and Jason S. Anderson in 2011, and the type species is Rubeostratilia texensis. The genus name comes from the Latin translation of 'redbeds' in reference to the Texas redbeds that produced both the holotype and many other early Permian fossils. The species name is for the state of Texas. The holotype and only known specimen was collected in 1941 from the Nocona Formation exposures in Clay County by a Works Projects Administration project that was transferred to the Field Museum of Natural History through an interinstitutional exchange with the Texas Memorial Museum.

Georgenthalia is an extinct genus of dissorophoid temnospondyl from the Lower Permian. It is an amphibamid which lived in what is now the Thuringian Forest of central Germany. It is known from the holotype MNG 11135, a small, complete skull. It was found in the Bromacker locality of the Tambach Formation. It was first named by Jason S. Anderson, Amy C. Henrici, Stuart S. Sumida, Thomas Martens and David S. Berman in 2008 and the type species is Georgenthalia clavinasica.

Olsoniformes Taxon of temnospondyl amphibians (fossil)

Olsoniformes is a clade of dissorophoid temnospondyls. It includes the families Dissorophidae and Trematopidae. Most members of the clade were highly adapted to a terrestrial lifestyle. The clade was named in 2008 and is defined as the least inclusive clade containing Dissorophus multicinctus and Acheloma cumminsi but not Amphibamus grandiceps, Micromelerpeton credneri, and Apateon pedestris. Olsoniforms share various features such as a stout and low ilium and a thin cultriform process.

Thuringothyris is an extinct genus of Early Permian eureptiles known from the Thuringian Forest in central Germany.

<i>Rotaryus</i> Extinct genus of amphibians

Rotaryus is an extinct genus of Early Permian trematopid dissorophoid temnospondyl known from the Free State of Thuringia of central Germany.

Amphibamiformes is an unranked clade with Dissorophoidea created by Schoch (2018). It encompasses all of the taxa traditionally considered to be "amphibamids", branchiosaurids, and hypothetically lissamphibians under the traditional temnospondyl hypothesis of lissamphibian origins. These taxa are typically small-bodied dissorophoids and form the sister group to Olsoniformes, which comprises dissorophids and trematopids.

This list of fossil amphibians described in 2020 is a list of new taxa of fossil amphibians that were described during the year 2020, as well as other significant discoveries and events related to amphibian paleontology that occurred in 2020.

References

  1. Berman, David S.; Reisz, Robert R.; Eberth, David A. (1987). "A new genus and species of trematopid amphibian from the Late Pennsylvanian of north-central New Mexico". Journal of Vertebrate Paleontology. 7 (3): 252–269. doi:10.1080/02724634.1987.10011659.
  2. Berman, David S.; Reisz, Robert R.; Eberth, David A. (1985). "Ecolsonia cutlerensis, an early Permian dissorophid amphibian from the Cutler Formation of north-central New Mexico". New Mexico Bureau of Mines and Minerals Research Circular. 191: 1–31.
  3. Schoch, Rainer R.; Milner, Andrew R. (2014). Handbuch der Paläoherpetologie Part 3A2. Temnospondyli I. Stuttgart: Verlag Dr. Friedrich Pfeil. ISBN   9783931516260.
  4. Berman, David S.; Henrici, Amy C.; Martens, Thomas; Sumida, Stuart S.; Anderson, Jason S. (2011). "Rotaryus gothae , a New Trematopid (Temnospondyli: Dissorophoidea) from the Lower Permian of Central Germany". Annals of Carnegie Museum. 80 (1): 49–65. doi:10.2992/007.080.0106. ISSN   0097-4463.
  5. Sumida, Stuart S.; Berman, David S.; Martens, Thomas (1998). "A new trematopid amphibian from the Lower Permian of central Germany". Palaeontology. 41 (4): 605–629.
  6. Polley, Brendan P.; Reisz, Robert R. (2011). "A new Lower Permian trematopid (Temnospondyli: Dissorophoidea) from Richards Spur, Oklahoma". Zoological Journal of the Linnean Society. 161 (4): 789–815. doi: 10.1111/j.1096-3642.2010.00668.x . ISSN   0024-4082.