Pelagornithidae - Taxonomy, Systematics and Evolution - Genera and Unidentified Specimens

Genera and Unidentified Specimens

Due to the fragmented and crushed state of most pseudotooth bird remains, it is not clear whether the roughly one dozen genera that have been named are all valid. Only the beaks are robust and distinctive enough to allow for good taxonomic delimitation, and even these are usually found as broken pieces. For example, Argilliornis and Neptuniavis were recently found to be arm and leg bones, respectively, of Dasornis, which until then was only known from skull bones. Size is generally regarded as reliable marker for generic diversity, but care just be taken to ascertain whether smallish specimens are not from young birds.

Tentatively, the following genera are recognized:

  • Pseudodontornis (Late Paleocene ?–? Late Oligocene of Charleston, South Carolina, USA) – polyphyletic (type species in Palaeochenoides/Pelagornis)?
  • "Odontoptila" (Late Paleocene/Early Eocene of Ouled Abdoun Basin, Morocco) – a nomen nudum; preoccupied
  • Odontopteryx (Late Paleocene/Early Eocene of Ouled Abdoun Basin, Morocco – Middle Eocene of Uzbekistan) – including "Neptuniavis" minor, may include "Pseudodontornis" longidentata, "P." tschulensis and Macrodontopteryx
  • Dasornis (London Clay Early Eocene of Isle of Sheppey, England) – including Argillornis, "Lithornis" emuinus and "Neptuniavis" miranda; may include "Odontopteryx gigas" (a nomen nudum), "Pseudodontornis" longidentata and Gigantornis
  • Macrodontopteryx (London Clay Early Eocene of England) – may include "Pseudodontornis" longidentata and/or belong in Odontopteryx
  • cf. Odontopteryx (Early Eocene of Virginia, USA)
  • Gigantornis (Ameki Middle Eocene of Ameki, Nigeria) – may belong in Dasornis
  • cf. Odontopteryx (Middle Eocene of Mexico)
  • Pelagornithidae gen. et sp. indet. (Middle Eocene of Mount Discovery, Antarctica) – same as large Seymour Island specimen/Dasornis/Gigantornis?
  • Pelagornithidae gen. et sp. indet. (Middle Eocene of Etterbeek, Belgium) – Dasornis/Macrodontopteryx?
  • "Aequornis" (Middle Eocene of Kpogamé-Hahotoé, Togo) – a nomen nudum
  • Pelagornithidae gen. et spp. indet. (La Meseta Middle/Late Eocene of Seymour Island, Antarctica) – two species? Same as Mount Discovery specimen/Dasornis/Gigantornis, Odontopteryx?
  • Pelagornithidae gen. et sp. indet. (Late Eocene of France)
  • Pelagornithidae gen. et sp. indet. (Late Eocene of Kazakhstan) – may belong in Zheroia
  • Pelagornithidae gen. et sp. indet. (Eocene of South Shetland Islands, South Atlantic)
  • cf. Dasornis (Late Eocene/Early Oligocene of Oregon, USA) – Cyphornis?
  • cf. Macrodontopteryx (Early Oligocene of Hamstead, England) – may belong in Proceriavis
  • Pelagornithidae gen. et sp. indet. (Early Oligocene of Japan)
  • Caspiodontornis (Late Oligocene of Pirəkəşkül, Azerbaijan) – may belong in Guguschia
  • Palaeochenoides (Late Oligocene of South Carolina, USA) – may include Pseudodontornis longirostris or belong in Pelagornis
  • Pelagornithidae gen. et sp. indet. (Late Oligocene of South Carolina, USA)
  • Pelagornithidae gen. et sp. indet. (Yamaga Late Oligocene of Kitakyushu, Japan) – Osteodontornis?
  • Tympanonesiotes (Late Oligocene or Early Miocene of Cooper River, USA)
  • Cyphornis (Early Miocene of Carmanah Point, Vancouver Island, Canada) – may include Osteodontornis
  • Osteodontornis (Early Miocene – Early Pliocene) – may belong in Cyphornis
  • Pelagornis (Early Miocene of Armagnac, France – Early Pleistocene of Ahl al Oughlam, Morocco) – may include Pseudodontornis longirostris, Palaeochenoides
  • Pelagornithidae gen. et spp. indet. (Early? Miocene – Early Pliocene of E USA) – 2–3 species? Pelagornis?
  • cf. Osteodontornis (Capadare Middle Miocene of Cueva del Zumbador, Venezuela)
  • cf. Osteodontornis/Pelagornis (?Middle/Late Miocene of North Canterbury, New Zealand)
  • cf. Pelagornis (Bahía Inglesa Middle Miocene of Chile – Early Pliocene of Chile and Peru) – 2 species?
  • cf. Osteodontornis (Pisco Middle Miocene –? Early Pliocene of Peru) – 2 species?
  • "Pseudodontornis" stirtoni (Miocene or Pliocene of Motunau Beach, New Zealand) – sometimes Neodontornis
  • Pelagornithidae gen. et sp. indet. (Yushima Early Pliocene of Maesawa, Japan) – Osteodontornis?
  • cf. "Pseudodontornis" stirtoni (Tangahoe Mudstone Middle Pliocene of Hawera New Zealand)
  • Pelagornithidae gen. et sp. indet. (Dainichi Early Pleistocene of Kakegawa, Japan) – Osteodontornis?
  • Pelagornis sp. (Late Pliocene of California, USA: Boessenecker and Smith; 2011)

Some other Paleogene (and in one case possibly Late Cretaceous) birds, typically taxa known only from the most fragmentary remains, might also be pelagornithids. They are not usually placed here, but the fossils' large size and the known similarities of certain pseudotooth birds' bones to those of other lineages warrant further study. The genera in question are Laornis, Proceriavis, Manu and Protopelicanus.

Read more about this topic:  Pelagornithidae, Taxonomy, Systematics and Evolution

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