New Cretaceous crabs (Crustacea, Brachyura) from Moscow Oblast and Dagestan (Russia): patterns in phylogeny and morphospace of the oldest eubrachyurans (Dorippoidea)

Four new brachyuran species, assigned to two genera and one existing genus, are recorded from Lower Upper Cretaceous strata of Moscow Oblast (Moskovskaya Oblast) Dagestan, Russia. Three taxa, Personadorippe levashiensis gen. et sp. nov., Levashidromites cornutus nov. Vectis collinsi were recovered Aptian in Dagestan; these constitute the first formal description crabs northern Caucasus. Of these, represents oldest eubrachyuran known date, being middle age thus predating late Telamonocarcinus antiquus Luque, 2014 (see 2014a) Colombia. A single carapace kalashnikovi constitutes ever record deposits region. only third species outside United Kingdom. The genus is reassessed here reassigned Viaiidae, which now comprises three genera. Rathbunopon? atherfieldense Wright, 1997 also transferred Vectis. family Longodromitidae restricted six genera, inclusive a diagnosis supplied. Navarrara, previously Longodromitidae, Telamonocarcinidae. Withersella Telamonocarcinidae; dorippoid (and hence, currently eubrachyuran) crab. described on basis follows shortly after. Eodorippe connori Nyborg, Garassino, Vega Kovalchuck, 2019 Carapace tripartition branchial condensation, i.e., ratio between median portion relative distance groove cervical groove, used as important proxy characters for reconsidering taxonomic placement primitive crabs. Phylogenetic analyses assessment phylomorphospace have revealed that herein part Jurassic–Cretaceous radiation This proceeded via high-magnitude morphological shift away morphology typical Tanidromites, with subsequent expansion all directions morphospaces occupied.