Megapaloelodus is an extinct genus of stem flamingo of the family Palaelodidae. Megapaloelodus is primarily known from Miocene America, from South Dakota and Oregon in the north to Argentina in the south, but the species Megapaloelodus goliath was found in Europe. Additionally, one unnamed species was discovered in Miocene sediments from Namibia. Due to a lack of skull material, little can be said about the ecology of Megapaloelodus. Species of this genus are typically larger than those of Palaelodus and appear to have inhabited similar brackish lake environments. Additionally, they may have been capable of "locking" their legs in a standing position.
Megapaloelodus was named by American Alden H. Miller in 1944 on the basis of a fossil femur and tarsometatarsus collected from the lower Miocene Rosebud Formation of South Dakota. Recognizing similarities to fossils of Palaelodus, Miller described the material as a new genus of phoenicopteriform he named Megapaloelodus. Initially, Miller was under the impression that Megapaloelodus was a missing link between the basal Palaelodus and derived flamingos.[1] In 1950 Loye H. Miller described the fragment of a tibiatarsus and an ulna from the late Miocene of California, also referring it to M. connectens. Miller notes that the California bones presents a sizable gap in both space and time while also not overlapping with any of the type material established six years prior. However, in the description he refers to the axiom "Things that differ in the same way from the same thing do not differ from each other." Through this he reasoned that, as the Californian fossil differs from Palaelodus in similar ways as the fossils from South Dakota, they could have belonged to the same species. Although this conclusion was acknowledged as being tentative, Miller further explained that it seemed more reasonable than to establish a new species on such fragmentary remains.[2] In addition to further finds from California,[3] a second species was described from Juntura, Oregon by Pierce Brodkorb, M. opsigonus.[4] This species may have also occurred further south in Mexico.[5] In 1983 Jacques Cheneval published a major revision of the palaelodids of Saint-Gérand-le-Puy. Besides agreeing with prior studies that synonymized many of the European species, he also transferred Palaelodus goliath to the genus Megapaloelodus.[6] Czech paleontologist Jiří Mlíkovský disagreed with this assessment in 2002 and instead suggested that Megapaloelodus should be synonymized with Palaelodus. However, this taxonomic treatment of the genus as a whole has been met with criticism and is considered premature by other authors.[7] In 2009 several specimens from Argentina previously only identified as an indetermined phoenicopterid were described as the species Megapaloelodus peiranoi.[8]
The name Megapaloelodus combines the Ancient Greek word "mega" meaning "great" with a misspelling of the name Palaelodus, roughly translating to "ancient inhabitant of marshes",[4] after the closely related genus primarily known from European deposits. The name was chosen to reflect the fact that the first discovered Megapaloelodus remains, belonging to M. connectens, appeared to have been larger than the already big Palaelodus goliath.[1][2] This is rendered somewhat ironic as subsequent research has placed Palaelodus goliath in Megapaloelodus as well.