A rich and diverse tanaidomorphan (Crustacea: Tanaidacea) assemblage associated with Early Cretaceous resin-producing forests in North Iberia: palaeobiological implications

The extinct tanaidomorphan diversity from Early Cretaceous Spanish amber, currently comprising 26 specimens, is reassessed. The fossil family Alavatanaidae Vonk &amp; Schram, 2007, described from Spanish amber, is revised on account of new preparation of type specimens and the discovery of new material. The described tanaidomorphan taxa are classified within the superfamily Paratanaoidea. An emended diagnosis for Alavatanaidae is provided, as well as for the genera <i>Alavatanais</i> Vonk &amp; Schram, 2007 and <i>Proleptochelia</i> Vonk &amp; Schram, 2007, and their respective species <i>Alavatanais carabe</i> Vonk &amp; Schram, 2007 and <i>Proleptochelia tenuissima</i> Vonk &amp; Schram, 2007. Three new species, two of them classified in a new genus each, are described: <i>Alavatanais margulisae</i> Sánchez-García, Peñalver &amp; Delclòs sp. nov., <i>Eurotanais terminator</i> Sánchez-García, Peñalver &amp; Delclòs gen. et sp. nov. and <i>Electrotanais monolithus</i> Sánchez-García, Peñalver &amp; Delclòs gen. et sp. nov. <i>Proleptochelia euskadiensis</i> Vonk &amp; Schram, 2007 is considered a junior synonym of <i>A. carabe</i>, and the genus <i>Proleptochelia</i>, together with its type and only species <i>P. tenuissima</i>, is left without familial placement within Paratanaoidea. Within this superfamily, Alavatanaidae is closely related to Leptocheliidae. Also, morphological variability due to sexual dimorphism in the studied paratanaoids has been determined. Multiple lines of taphonomic and palaeobiological evidence indicate that the Spanish amber tanaids were most likely inhabitants of wet or moist forest floors.http://zoobank.org/urn:lsid:zoobank.org:pub:DC943B18-A01C-412C-8378-C644FEFDA716