Paleocene echinoid faunas of the eastern United States

Abstract

Twenty-one species of echinoid are reported from Paleocene rocks of the eastern United States along the outcrop belt from Texas to New Jersey. Six of these are strictly early Paleocene age (Danian), nine strictly late Paleocene age (Thanetian), five range throughout the Paleocene, and one previously reported Paleocene species (Diplodetus moscovensis) is most likely a Cretaceous species. Two new species are described, Salenia palmyra n. sp., from the Danian Clayton Formation in Alabama and Georgia, and Ova rancoca n. sp., from the Thanetian Vincentown Formation in New Jersey. One new species from the Clayton Formation in Mississippi, Arbaciella? sp., is left in open nomenclature.

Phylogeny and biogeography of some Cretaceous spatangoid echinoids with special emphasis on taxa from the Western Interior Seaway

“…They have also been incorporated into phylogenetic analyses that considered both living and fossil taxa (Villier et al, 2004; Stockley et al, 2005; Saucède et al, 2007; Kroh and Smith, 2010; Kroh et al, 2014). The goal of the present study is to focus on species-level phylogenetic relationships of Cretaceous spatangoids, with special emphasis on taxa from the WIS, although it was not possible to consider to any great extent the diverse range of taxa present in the Mississippi Embayment, an important and related biogeographic region (see Zachos, 2017), as taxa in this region primarily radiated too late to be relevant to the present analysis. The present study also uses the phylogenetic perspective to consider aspects of the biogeographic relationship between the WIS and other parts of the Cretaceous world.…”