Pliocene insects (Arthropoda: Insecta) and arachnids (Artropoda: Arachnida) from the Sierra de Tesistán, Jalisco, Mexico

The presence of fossil arthropods with a very good preservation is recorded in a locality in Jalisco, Mexico. The specimens were collected from lacustrine sediments formed during the early Pliocene (Zanclian), which have their origin in the accumulation of volcanic sedimentary material in a body of water, formed after the flooding of a collapsed volcanic caldera. The locality is in Sierra de Tesistán, in the municipality of Zapopan, Jalisco. Twelve fossil specimens were identified, which were collected between 2017 and 2019, resulting in the presence of arthropods of the Insecta and Arachnida classes. Within the Class Insecta, four orders were recorded: Hemiptera (four specimens), Coleoptera (six specimens) and Diptera (one specimen); In the Order Arachnida there is only one specimen from the Araneae family. This is the first record of fossil insects and arachnids for the state of Jalisco, which adds to the extensive fossil record of the entity.