''Labidosaurus'' (from el, λᾰβῐ́δος , 'forceps' and el, σαῦρος , 'lizard') is an extinct genus of

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

from the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

period of North America. Fossils have been discovered in

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

. It was heavily built, resembling a

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

with a large head, and measuring about long. Unlike many other captorhinids it had a single row of sharp, conical teeth in its jaws, and its dietary habits are assumed to have been

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

. A lower jaw of ''Labidosaurus'' was described in 2011 that shows evidence of

osteomyelitis Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...

, or an infection of the bone. It is the earliest known example of an infection in a land vertebrate. The infection probably developed because the

pulp Pulp may refer to: * Pulp (fruit), the inner flesh of fruit Engineering * Dissolving pulp, highly purified cellulose used in fibre and film manufacture * Pulp (paper), the fibrous material used to make paper * Molded pulp, a packaging material * ...

cavity of a broken

dentary In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

tooth was exposed to

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

. Although another tooth would have replaced the broken one, regeneration would have been slow. ''Labidosaurus'' and other derived captorhinids had teeth that were deeply implanted in the jaws. This deep implantation limited tooth replacement, meaning that a broken tooth would have been exposed for a long period of time.

References

Permian reptiles of North America Captorhinids Cisuralian genus first appearances Cisuralian genus extinctions Prehistoric reptile genera {{permian-reptile-stub