Konzhukovia

Konzhukovia was named in honor of Russian paleontologist Elena Dometevna Konzhukova (wife of paleontologist Ivan Yefremov) in 1991 by Russian paleontologist Yuri M. Gubin, based on a specimen Konzhukova had called Melosaurus vetustus in 1955.[5] The name was misspelled as Konzohuvia by Schoch and Milner.[6] The specific name sangabrielensis (a species type) is derived from the municipality where the specimen was recovered in southern Brazil.[2]

The Konzhukovia skull has an overall triangular appearance due to the lateral margins of the snout expanding parallel and then diverging from each other and the most anterior portion of the snout is rounded.[2] The skull contains both infra- and supraorbital sensory sulci, the infraorbital sulcus is located on the maxilla and runs posteriorly to the lacrimal while the supraorbital sulcus extends anteriorly to the naris.[2] The orbits are elongate and the skull shows paired anterior palatal vacuity.[7] The orbits are positioned after the midline of the skull and are relatively widely separated from each other.[8] The skull contains pleurodont dentition and the maxilla and premaxilla of recovered specimens carry evidence of more than 30 teeth.[2] The tooth row runs straight between the vomerine fangs, the vomerine tusks and palatine tusks are equal in size, and the maxillary teeth are anteroposteriorly compressed.[2] Comparing the three species, K. sangabrielensis was almost twice the size of both K. tarda and K. vetusta and appeared to be very robust in overall shape.[2] Pacheco used phylogenetic inference to infer that K. sangabrielensis was missing the septomaxilla due to the fact that the absence of this bone is a common feature in its relatives, as it was not visible in the specimen found representing K. sangabrielensis.[2] All three Konzhukovia species exhibit oval nostrils with wide lateral openings located on the anterior edge of the snout (Pacheco, 2016). The premaxilla, maxilla, and nasal all make contact with the nostrils edges and the prefrontal is fragmented.[2] The maxilla is what forms most of the lateral portion of the choanae, giving an overall long and oval form which is seen in all konzhukoviids and several other temnospondyls.[2] The vomer contacts the maxilla and its lateral process reaches the same level as the palatine tucks.[2] The cultriform process of the parasphenoid in K. vetusta and K. tarda is inserted between the vomers.[2] These animals have interpterygoid vacuities which appear to be oval and elongated, the palatine is what forms the most anterior part of the vacuity.[2] The pterygoids are fragmented and in K. tarda, the palatine ramus of the pterygoid runs anteriorly to the palatine tusks, unlike in K. vetusta where the palatine ramus ends at the same level.[9] The illiac blade is known to be not bifurcated in K. vetusta.[10]

The Rio do Rasto Formation, where K. sangabrielensis was recovered, ranges from Guadalupian to Lopingian.[12] The Permian specimens that have been found in southern South America only consist of fossil faunas in the Rio do Rasto Formation.[2]

The Southern Urals area of European Russia, where K. tarda and K. vetusta were found, have been the recovery site of many amphibians and reptiles from the Upper Permian, dating back to the 1940s.[11] The area with rich deposits consists of 900,000 km² of land between River Volga in the northwest and Orenburg in the southwest.[11] A continental succession consisting of mudstones, siltstones, and sandstones provides specimens from the last two stages of the Permian, the Kazanian and Tatarian.[11]