International Geological Journal - Official Journal of the Carpathian-Balkan Geological Association

Taxonomic diversity of cockroach assemblages (Blattaria, Insecta) of the Aptian Crato Formation (Cretaceous, NE Brazil)

Pages: 433 - 450

Authors: SHIH-WEI LEE

Abstract: A comprehensive revision of 981 specimens of fossil cockroaches from the Lower Cretaceous laminated limestones of the Crato Formation of Northeast Brazil shows that they belong to eleven taxa, including Piniblattella limai, P. magna sp. n., Perlucipecta santanensis. sp. n., Raptoblatta waddingtonae; Ocelloblattula santanensis sp. n., Elisama brevis (= E. americana, syn.n.), E. hindwingnii sp. n., Ponopterix axelrodi (= P. maxima syn.n.), Umenopterix burkhardi comb. n., and Cratovitisma oldreadi (Umenocoleidae = Cratovitismidae syn.n. = Ponopterixidae syn.n.). The family Ectobiidae is numerically most abundant in the assemblage of cockroaches of the Crato Formation (83 % of cockroaches), followed by Blattulidae (13 %) and Umenocoleidae (4 %). 79.2 % of specimens are complete and fully articulated. Members of the family Alienopteridae are probably also present. Representatives of a relatively common Mesozoic superfamily Caloblattinoidea are missing. With the exception of the endemic genera Cratovitisma and Raptoblatta and the exclusively Gondwanan genus Ocelloblattula, all other genera were cosmopolitan. Taxonomic richness of cockroaches of the Crato Formation is thus rather low, and consists of geologically long-ranging and geographically-widespread genera, genera restricted to Gondwana, and short-ranging endemic genera found in the Crato Formation only.

Keywords: Fossil insects, new species, Blattodea, variability, taphonomy, Mesozoic, Early Cretaceous, Gondwana

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