Systematic and palaeoecological significance of the first record of Pygocephalomorpha females bearing oöstegites (Malacostraca, Peracarida) from the lower Permian of southern Brazil

Abstract

Malacostracan crustaceans of the fossil order Pygocephalomorpha are conspicuous elements in brackish to freshwater faunas in the upper Carboniferous of Laurentia and lower Permian of Gondwana. A pronounced sexual dimorphism is recognizable within its members, with Pygocephalomorpha females bearing o€ ostegites: modified epipodites that hold a brood pouch where the eggs develop until juvenile stage, with no planktonic dispersal of larvae. The preservation of o€ ostegites is quite rare and is described here for the first time from the American continents. The specimens, ventrally preserved Liocaris huenei females bearing o€ ostegites, come from the Irati Formation, a lower Permian sequence of the Paran a Basin, from an outcrop in southern Brazil. The o€ ostegites are similar to those previously described for Pygocephalomorpha, displaying seven pairs of overlapping epipodites that cover the whole cephalothorax.

Marsupial brood care in Cretaceous tanaidaceans

“…maternus Broly et al ., in press, from the Aquitanian Chiapas amber 39 , the former two myodocope ostracods and the latter two isopods. Other evidence of reproductive strategies in fossil crustaceans are otherwise indirect (refs 37 and 40 and references therein), or are restricted to putative in situ eggs or embryos of a bradoriid species 41 , 42 , a waptiid 43 , a tealliocaridid 44 , a syncarid 45 , two branchiopod species 46 , 47 , and a few other ostracods 48 .…”