Wednesday, November 28, 2012

[Cetology • 2012] Miocaperea pulchra • Comparative osteology and phylogenetic relationships of Miocaperea pulchra, the first fossil pygmy right whale (Cetacea, Mysticeti, Neobalaenidae) | found from the upper Miocene Pisco Formation at Aguada de Loma, Peru


the skulls of Caperea (left) and Miocaperea (right), from Bisconti (2012).

Abstract 
A fossil pygmy right whale (Cetacea, Mysticeti, Neobalaenidae) with exquisitely preserved baleen is described for the first time in the history of cetacean palaeontology, providing a wealth of information about the evolutionary history and palaeobiogeography of Neobalaenidae. This exquisitely preserved specimen is assigned to a new genus and species, Miocaperea pulchra gen. et sp. nov., and differs from Caperea marginata Gray, 1846, the only living taxon currently assigned to Neobalaenidae, in details of the temporal fossa and basicranium. A thorough comparative analysis of the skeleton of M. pulchra gen. et sp. nov. and C. marginata is also provided, and forms the basis of an extensive osteology-based phylogenetic analysis, confirming the placement of M. pulchra gen. et sp. nov. within Neobalaenidae as well as the monophyly of Neobalaenidae and Balaenidae; the phylogenetic results support the validity of the superfamily Balaenoidea. No relationship with Balaenopteroidea was found by the present study, and thus the balaenopterid-like morphological features observed in C. marginata must have resulted from parallel evolution. The presence of M. pulchra gen. et sp. nov. around 2000 km north from the northernmost sightings of C. marginata suggests that different ecological conditions were able to support pygmy right whale populations in what is now Peru, and that subsequent environmental change caused a southern shift in the distribution of the living neobalaenid whales.

Keywords: Balaenoidea; Caperea marginata; Miocene; Peru; phylogeny 


Three-dimensionally preserved baleen in Miocaperea

Bisconti, M. 2012. Comparative osteology and phylogenetic relationships of Miocaperea pulchra, the first fossil pygmy right whale genus and species (Cetacea, Mysticeti, Neobalaenidae). Zoological Journal of the Linnean Society. 166: 876-911. DOI: 10.1111/j.1096-3642.2012.00862.x 

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