Palaelodus

From Wikipedia, the free encyclopedia

Palaelodus
Fossil range: Middle Oligocene to Middle Pleistocene

Fossil

Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Phoenicopteriformes
Family:	Palaelodidae
Genus:	Palaelodus A. Milne-Edwards, 1863

Species

Palaelodus ambiguus (type)
Palaelodus gracilipes (disputed)
Palaelodus crassipes (disputed)
Palaelodus germanicus (disputed)
Palaelodus pledgei
Palaelodus wilsoni (disputed)

Synonyms

Probalearica Lambrecht, 1933
Paloelodus (lapsus)
Palaeolodus (lapsus)

Palaelodus is an extinct genus of birds distantly related to flamingos. They were slender birds with long, thin legs and a long neck. Little is known about the shape of their skull or beak. Some paleontologists think Palaelodus was able to swim under water, chasing prey, but the morphology of their feet seems not very well adapted for diving. Rather, it is more likely that they were adapted to browsing for food while swimming or standing in shallow water.

The family, Palaelodidae, is the sister taxon of modern flamingos, and the order Phoenicopteriformes, to which both belong, probably evolved from a grebe-like ancestor. It is easy to see how a bird like Palaelodus represents an intermediate form between a diving, fish-eating grebe and a wading, invertebrate-filtering flamingo. This does not mean that the palaelodids are the ancestors of the flamingos. Rather, they were a sister group that remained in the ecological niche of their common ancestor.

The number of species in the genus is disputed. The species P. ambiguus was found in Middle Oligocene to Middle Miocene (c. 29-12 mya) deposits of Western and Central Europe, being rare in Oligocene and much more common in Miocene strata (Hugueney et al., 2003). The Romanian fossil Grus miocaenicus is sometimes considered a synonym of this species. Other, somewhat doubtful species described from the Late Oligocene to Early Miocene (c. 28-23 mya) of French inland sites are P. gracilipes and P. crassipes which are most common in the Late Oligocene and later are replaced by P. ambiguus (Hugueney et al., 2003). From Late Oligocene to Middle Miocene (c. 28-12 mya) sites in Australia, the species P. pledgei was described. P. wilsoni was found in Middle Pleistocene deposits (roughly half a million years ago) in Australia; given the large temporal gap, it might not belong into this genus. On the other hand, the supposed crane Pliogrus germanicus most likely belongs into this genus. Sometimes, Megapalaolodus goliath is included in Palaelodus too.

[edit] References

Hugueney, Marguerite; Berthet, Didier; Bodergat, Anne-Marie; Escuillié, François; Mourer-Chauviré, Cécile & Wattinne, Aurélia (2003): La limite Oligocène-Miocène en Limagne-changements fauniques chez les mammifères, oiseaux et ostracodes des différents niveaux de Billy-Créchy (Allier, France). Geobios 36: 719-731 [Article in French with English abstract] doi:10.1016/j.geobios.2003.01.002 (HTML abstract)

Milne-Edwards, Alphonse (1863): Mémoire sur la distribution géologique des oiseaux fossiles et description de quelques espèces nouvelles. Annales des Sciences Naturelles 4(20): 132-176.