title: Early Miocene amber inclusions from Mexico reveal antiquity of mangrove-associated copepods.
abstract: Copepods are aquatic microcrustaceans and represent the most abundant metazoans on Earth, outnumbering insects and nematode worms. Their position of numerical world predominance can be attributed to three principal radiation events, i.e. their major habitat shift into the marine plankton, the colonization of freshwater and semiterrestrial environments, and the evolution of parasitism. Their variety of life strategies has generated an incredible morphological plasticity and disparity in body form and shape that are arguably unrivalled among the Crustacea. Although their chitinous exoskeleton is largely resistant to chemical degradation copepods are exceedingly scarce in the geological record with limited body fossil evidence being available for only three of the eight currently recognized orders. The preservation of aquatic arthropods in amber is unusual but offers a unique insight into ancient subtropical and tropical ecosystems. Here we report the first discovery of amber-preserved harpacticoid copepods, represented by ten putative species belonging to five families, based on Early Miocene (22.8 million years ago) samples from Chiapas, southeast Mexico. Their close resemblance to Recent mangrove-associated copepods highlights the antiquity of the specialized harpacticoid fauna living in this habitat. With the taxa reported herein, the Mexican amber holds the greatest diversity of fossil copepods worldwide.
authors.affiliation: Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom.
authors.forename: Rony
authors.initials: R
authors.lastname: Huys
authors.affiliation: El Colegio de la Frontera Sur (ECOSUR), A.P. 424, 77000 Chetumal, Quintana Roo, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Suárez-Morales
authors.affiliation: Posgrado en Ciencias de La Tierra, UNAM, Ciudad Universitaria, Coyoacán, México DF 04510, Mexico.
authors.forename: María de Lourdes
authors.initials: ML
authors.lastname: Serrano-Sánchez
authors.affiliation: Instituto de Geología, UNAM, Ciudad Universitaria, Coyoacán, México DF 04510, Mexico.
authors.forename: Elena
authors.initials: E
authors.lastname: Centeno-García
authors.affiliation: Instituto de Geología, UNAM, Ciudad Universitaria, Coyoacán, México DF 04510, Mexico.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Vega
mesh_terms: D018647:Amber; D000818:Animals; D005075:Biological Evolution; D033342:Copepoda / Q000502:physiology*; D017753:Ecosystem; D005580:Fossils; D008800:Mexico; D010933:Plankton / Q000502:physiology*; D013559:Symbiosis; D053833:Wetlands
chemical_list: D018647:Amber