New productide brachiopods (Productoidea) from the Carboniferous of Ixtaltepec Formation, Oaxaca, Mexico

Abstract

AbstractFrom the Santiago Ixtaltepec area, in Oaxaca State, southern Mexico, 11 species of productoid brachiopods, including a new genus and five new species, are described.Semicostellasp.,Antiquatoniasp.,Keokukia? sp.,Inflatia inflata,Reticulatiacf.R.huecoensis,Buxtonia websteri,Weberproductus donajiaen. gen. n. sp.,Dictyoclostus transversumn. sp.,Inflatia coodzavuiin. sp.,Buxtonia inexpletucostan. sp., andFlexaria magnan. sp. were collected from eight stratigraphic levels of the Ixtaltepec Formation. The presence ofSemicostellasp.,Keokukia? sp. andInflatia inflatain the basal strata, Units 1 to 3, of the formation indicate a Viséan-Serpukhovian (Late Mississippian) age.Reticulatiacf.R.huecoensisandBuxtonia websteri, found in Units 6 to 8, confirm the Pennsylvanian age for upper strata of the Ixtaltepec Formation.InflatiaandFlexariaare present in the uppermost beds of the formation so it is possible to extend their upper stratigraphic range to the Middle Pennsylvanian. All these taxa also occur in the United States Midcontinent, suggesting that during the Carboniferous the epicontinental sea extended at least to central Mexico.