Extant-and-fossil
Guides
Cupes
Cupes is a genus of reticulate beetles in the family Cupedidae, containing a single extant species, Cupes capitatus, native to eastern North America. The genus has a remarkably diverse fossil record, with numerous extinct species described from Eocene to Pliocene deposits in Europe and China. The extant species is small, averaging 7.8 mm in length, with distinctive orange head ornamentation. The disjunct distribution—living species in North America versus abundant fossils in Europe—suggests a formerly widespread group with a contracted modern range.
Diplocoelus
Diplocoelus is a genus of small beetles in the family Biphyllidae, comprising approximately 45 described species distributed across multiple continents. The genus includes both extant species and one fossil species (D. probiphyllus) known from Baltic amber. Species within Diplocoelus exhibit considerable morphological diversity in body form and surface sculpturing. The genus was established by Guérin-Méneville in 1838.
Limulus
Atlantic Horseshoe Crabs
Limulus is a genus of horseshoe crabs in the family Limulidae, containing one extant species, Limulus polyphemus, commonly known as the Atlantic horseshoe crab. The genus also includes at least one confirmed fossil species, Limulus coffini, from the Late Cretaceous of the United States. Several other fossil species have been assigned to Limulus historically, though many have since been reclassified to other genera. The genus is distinguished from other horseshoe crab genera primarily by geographic distribution and subtle morphological features.