Pan-Alcidae

Pan-Alcidae is a clade of charadriiform birds containing the auks and their extinct relatives. It was named in 2011 by N.A. Smith, who defined it as all descendants of the common ancestor of the group Mancallinae and crown group auks (Alcidae).^[1]

Evolution and distribution

The earliest unequivocal fossils of pan-alcids are from the late Eocene, some 35 mya.^[1] The genus Miocepphus, (from the Miocene, 15 mya) is the earliest known from good specimens. Two very fragmentary fossils are often assigned to the Alcidae, although this may not be correct: Hydrotherikornis (late Eocene) and Petralca (Late Oligocene). Most extant genera are known to exist since the Late Miocene or Early Pliocene (c. 5 mya). Miocene fossils have been found in both California and Maryland, but the greater diversity of fossils and tribes in the Pacific leads most scientists to conclude that it was there they first evolved, and it is in the Miocene Pacific that the first fossils of extant genera are found. Early movement between the Pacific and the Atlantic probably happened to the south (since there was no northern opening to the Atlantic), later movements across the Arctic Ocean.^[2] The flightless subfamily Mancallinae which was apparently restricted to the Pacific coast of southern North America became extinct in the Early Pleistocene.

Classification

• Pan-Alcidae
  • †Hydrotherikornis? (Late Eocene of Oregon, USA)
  • †Pseudocepphus? (Middle - Late Miocene) – basal Alcinae?
  • †Subfamily Petralcinae?
    • Petralca (Early ?- Late Oligocene of Austria)
  • Subfamily †Mancallinae
  • Family Alcidae

References