Hreflangenus

Hreflangenus is a genus of extinct marine arthropods known from fossil specimens dating to the Early Triassic. The genus includes several species described from marine sedimentary rocks in the western Tethys region.

Taxonomy and naming: The name hreflangenus was coined in a 2012 description by paleontologists in reference to distinctive features noted in the fossils. Its precise placement within Arthropoda remains debated; some researchers place it in Trilobita, others in a stem group close to crustaceans.

Description: Hreflangenus specimens show a dorsoventrally flattened exoskeleton with a head shield and segmented body. The cephalon often bears marginal tubercles, and the thorax comprises a limited number of segments. Appendages are typically known from impression fossils, and the overall size of preserved individuals ranges from about 1 to 3 centimeters.

Distribution and habitat: Fossils attributed to hreflangenus have been found in limestone and sandstone beds dating to the Early Triassic in Europe and nearby regions. They are interpreted as inhabitants of shallow marine environments, living on or near soft substrata in relatively calm to moderately energetic waters.

Taxonomic status and significance: As part of the Early Triassic recovery fauna, hreflangenus contributes to understanding arthropod diversification after the Permian–Triassic mass extinction and sheds light on the tempo of marine ecosystem rebuilding during this interval.

See also: List of prehistoric arthropods, Early Triassic fauna, Paleontology of the Tethys region.