Systematics and biogeography of the “<i>Malvinella</i> group,” Calmoniidae (Trilobita, Devonian)

Abstract

Phylogenetic parsimony analysis forms a basis for classification of the Siegenian–Eifelian “Malvinella group,” a monophyletic taxon within the “Metacryphaeus group” of the family Calmoniidae. Fifty-one exoskeletal characters for Metacryphaeus Reed and 12 taxa of the “Malvinella group” yield a shortest length cladogram with a consistency index of 0.51. A classification based on retrieving the structure of this cladogram recognizes six genera: Malvinella Wolfart, Vogesina Wolfart, Palpebrops n. gen. (type P. donegalensis n. sp.), the sister taxa Parabouleia Eldredge and Bouleia Kozlowski, and Plesiomalvinella n. gen. [type P. pujravii (Wolfart)]. Palpebrops is more closely related to Vogesina than to Malvinella; Amazonian species are nested within this group as sister taxa to Andean or Amazon/Andean clades. Bolivian Belén Formation Malvinella buddeae n. sp. is an allopatric species distinct from Icla Formation M. haugi (Kozlowski). “Metacryphaeus” of recent revisions is a paraphyletic grade group including primitive species of the “Malvinella group.” Metacryphaeus australis (Clarke), M. tuberculatus (Kozlowski), and M. caffer (Salter) are endemic to the Paraná Basin, Andean Bolivia–Parnaíba Basin, and South Africa, respectively.</jats:p