2013/04/27 by Daniel T. Ksepka, Amy M. Balanoff, Michael A. Bell +1 · 4 citations
Earth and Planetary Sciences · Environmental Science · #Paleontology and Evolutionary Biology #Ichthyology and Marine Biology #Evolution and Paleontology Studies
paper · doi:10.1111/pala.12040
openalex publication_date 2013/04/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Podicipediformes is a cosmopolitan clade of foot‐propelled diving birds that, despite inhabiting marine and lacustrine environments, have a poor fossil record. In this contribution, we describe three new grebe fossils from the diatomite beds of the Late Miocene Truckee Formation (10.2 ± 0.2 Ma) of Nevada ( USA ). Two postcranial skeletons and an associated set of wing elements indicate that at least two distinct grebe species occupied the large, shallow Lake Truckee during the Miocene. Phylogenetic analysis of morphological data supports a basal divergence between a clade uniting the dabchicks ( T achybaptus , L imnodytes , P oliocephalus ) and a clade uniting P odilymbus , R ollandia , P odiceps and A echmophorus . Missing data, combined with a paucity of informative skeletal characters, make it difficult to place the Truckee grebes within either of these major clades. Given the weak projection of the cnemial crests compared with extant grebes, it also remains plausible that these specimens represent stem lineage grebes. Although more material is needed to resolve the phylogenetic position of the Truckee grebes, our analysis offers insight into the tempo of grebe evolution by placing the Miocene taxon T hiornis sociata within the dabchick clade. T hiornis sociata provides a minimum age calibration of 8.7 Ma for the basal divergence among dabchicks. Based on the recovery of a nonmonophyletic T achybaptus and placement of the Western Hemisphere ‘ T achybaptus ’ dominicus as the basal member of the otherwise exclusively Eastern Hemisphere dabchick clade, we resurrect the genus L imnodytes for this extant species ( L imnodytes dominicus ). Our results also nest the large, long‐necked A echmophorus grebes within the genus P odiceps , as the sister taxon to P odiceps major .