Tshekardocoleidae is an extinct family of stem group beetles, known from the Early Permian. They represent some of the earliest known beetles. They first appeared during the Cisuralian, before becoming extinct at the beginning of the Guadalupian. A claimed Jurassic record is doubtful. Like other primitive beetles, they are thought to have been xylophagous. The oldest known beetle, Coleopsis, was originally assigned to this family, but is now assigned to its own family Coleopsidae.
Tshekardocoleidae is an extinct family of stem group beetles, known from the Early Permian. They represent some of the earliest known beetles. They first appeared during the Cisuralian, before becoming extinct at the beginning of the Guadalupian. A claimed Jurassic record is doubtful. Like other primitive beetles, they are thought to have been xylophagous. The oldest known beetle, Coleopsis, was originally assigned to this family, but is now assigned to its own family Coleopsidae.
The Tshekardocoleidae are thought to have retained several plesiomorphies (ancestral characters) of Coleoptera in a broad sense. For instance, their elytra are flattened, lack epipleura (outer margins), cover the body loosely, and their tips extend beyond the apex of the abdomen. Their abdomens have a nearly cylindrical shape and are thought to have been flexible, apparently being able to strongly contract and expand. In extant beetles, the elytra are tight-fitting, forming a subelytral space which is absent in Tshekardocoleidae. The elytra also have remnants of veins, and have rows of "window punctures" between them. Such window punctures are also present in other stem-group beetle families, but in extant beetles are present only in Cupedidae and Ommatidae.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).