''Funcusvermis'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushr ...

caecilian Caecilians (; ) are a group of limbless, vermiform or serpentine amphibians. They mostly live hidden in the ground and in stream substrates, making them the least familiar order of amphibians. Caecilians are mostly distributed in the tropics ...

from the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a U.S. state, state in the Southwestern United States. It is the list of U.S. states and territories by area, 6th largest and the list of U.S. states and territories by population, 14 ...

. It is based on a large sample of jaws and other skull and postcranial fragments, discovered in an approximately 220 million years old layer of rock in the Blue Mesa Member of the

Chinle Formation The Chinle Formation is an Upper Triassic continental geological formation of fluvial, lacustrine, and palustrine to eolian deposits spread across the U.S. states of Nevada, Utah, northern Arizona, western New Mexico, and western Colorado. In ...

Petrified Forest National Park Petrified Forest National Park is an American national park in Navajo and Apache counties in northeastern Arizona. Named for its large deposits of petrified wood, the park covers about , encompassing semi-desert shrub steppe as well as highly ero ...

. There is a single species, called ''Funcusvermis gilmorei''. The identity of ''Funcusvermis'' as a

gymnophiona Caecilians (; ) are a group of limbless, vermiform or serpentine amphibians. They mostly live hidden in the ground and in stream substrates, making them the least familiar order of amphibians. Caecilians are mostly distributed in the tropics ...

n amphibian is supported by a range of traits, including a long additional tooth row in the jaw, a fused maxillopalatine bone in the skull, and a modified jaw with a pseudodentary and pseudoangular. Small

femora The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with t ...

(thigh bones) indicate that legs were still present in ''Funcusvermis'', despite its modern relatives being completely legless. ''Funcusvermis'' is the oldest known gymnophionan, and has the largest known sample of fossils referred to the group. Previously, both records were held by '' Eocaecilia micropodia'', an amphibian from the

Early Jurassic The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma ...

Kayenta Formation The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Traditionally has been suggested ...

of Arizona. The discovery of ''Funcusvermis'' provides a strong link between caecilians and other lissamphibians (

frogs A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

and

salamanders Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All te ...

), as well as extinct

dissorophoid Dissorophoideans are a clade of medium-sized, temnospondyl amphibians that appeared during the Moscovian in Euramerica, and continued through to the Late Permian and the Early Triassic of Gondwana. They are distinguished by various details of t ...

temnospondyls Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carb ...

such as ''

Gerobatrachus ''Gerobatrachus'' is an extinct genus of amphibamid temnospondyl (represented by the type species ''Gerobatrachus hottoni'') that lived in the Early Permian, approximately 290 million years ago (Ma), in the area that is now Baylor County, Texas. ...

''. It supports the consensus hypothesis for lissamphibian evolution, with Lissamphibia as a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...

group with a single common ancestor among the dissorophoids. Consequently, the anatomy of ''Funcusvermis'' helps to compare and contrast alternative hypotheses for lissamphibian origins. For example, a 2017 study proposed that caecilians were related to ''

Chinlestegophis ''Chinlestegophis'' is a diminutive Late Triassic stereospondyl that has been interpreted as a putative stem caecilian, a living group of legless burrowing amphibians. If ''Chinlestegophis'' is indeed both an advanced stereospondyl and a relative ...

'', a

stereospondyl The Stereospondyli are a group of extinct temnospondyl amphibians that existed primarily during the Mesozoic period. They are known from all seven continents and were common components of many Triassic ecosystems, likely filling a similar ecolog ...

from strata of the

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

. This study was scrutinized and its conclusions were rejected by the description of ''Funcusvermis''. The genus name translates to "funky worm", in reference to the funk song of the same name by the

Ohio Players Ohio Players is an American funk band, most popular in the 1970s. They are best known for their songs "Fire" and "Love Rollercoaster", and for their erotic album covers that featured nude or nearly nude women. Many of the women were models feat ...

. The species name honors collections manager Ned Gilmore of the

Academy of Natural Sciences of Drexel University The Academy of Natural Sciences of Drexel University, formerly the Academy of Natural Sciences of Philadelphia, is the oldest natural science research institution and museum in the Americas. It was founded in 1812, by many of the leading natu ...

Philadelphia, Pennsylvania Philadelphia, often called Philly, is the List of municipalities in Pennsylvania#Municipalities, largest city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, the List of United States cities by population, sixth-largest city i ...

, United States.

References

{{Taxonbar, from=Q116446290 Gymnophiona Late Triassic amphibians of North America Prehistoric amphibian genera Triassic Arizona Chinle fauna Norian life Transitional fossils Fossil taxa described in 2023