A new fossil talitrid amphipod from the lower early Miocene Chiapas amber documented with microCT scanning. (March 2020) - Hegna, Thomas A.
Abstract: The blind fossil amphipod, Caecorchestia bousfieldi, Hegna and Lazo-Wasem, new genus and species, is described from the lower Miocene Campo La Granja amber mines in Chiapas, Mexico, based on more than 130 specimens in diverse states of preservation. It is the second amphipod species to be described from Chiapas amber. C. bousfieldi belongs to the Talitridae, a family of amphipods that have successfully colonized terrestrial habitats. Exactly how fully terrestrial Caecorchestia bousfieldi was is unclear, and its blindness likely indicates that it occupied a cryptic habitat. A review of the amphipod fossil record is given which demonstrates that the amphipods first appeared as fossils in the Eocene. Highlights: First record of blind amphipods in Miocene amber. More than 100 specimens, from juveniles to adults, from corpses to decaying remains. Use of CTScan to observe detailed morphology. Confirmation of estuarine-cryptic environment for Campo La Granja amber, Chiapas. Occurrence in stratified amber pieces.