''Podiceps dixi'' is a possible extinct species of

grebe Grebes () are aquatic diving birds in the order (biology), order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Most grebes f ...

from the United States.

History

''P. dixi'' was part of 5000 bird fossils that were cataloged from Reddick,

Marion County, Florida Marion County is a county located in the North Central region of the U.S. state of Florida. As of the 2020 United States census, the population was 375,908. Its county seat is Ocala. Marion County comprises the Ocala, Florida Metropolitan S ...

. The material was collected by H. James Gut in 1950 and the species was described by the American

ornithologist Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", is a branch of zoology dedicated to the study of birds. Several aspects of ornithology differ from related discip ...

and

paleontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Pierce Brodkorb William Pierce Brodkorb (September 29, 1908, Chicago – July 18, 1992, Gainesville, Florida) was an American ornithologist and paleontologist. Interested in birds since childhood, he was taught to prepare birds at the age of 16. Later, he rec ...

in 1963. The species name "dixi" is named after the Dixie Lime Products Company where they had a mine located at the Reddick beds where the fossil was found.

Description

The holotype and only specimen (UF/PB 1113) is of a proximal end of the right

carpometacarpus The carpometacarpus is a bone found in the hands of birds. It results from the fusion of the carpal and metacarpal bone, and is essentially a single fused bone between the wrist and the knuckles. It is a smallish bone in most birds, generally fla ...

. It is similar to the living

horned grebe The horned grebe or Slavonian grebe (''Podiceps auritus'') is a relatively small and Threatened species, threatened species of waterbird in the family Podicipedidae. There are two subspecies, ''P. a. auritus'' (Slavonian grebe), which breed ...

(''P. auritus'') but somewhat larger.

Classification

Due to the overall similarity of the bone to those of horned grebes, as well as the fragmentary nature of it, some authors have question the validity of the species suggesting that the name be a junior synonym of ''P. auritus''.

Paleobiology

The age of the ''P. dixi'' limb element is that of the

Rancholabrean The Rancholabrean North American Land Mammal Age on the geologic timescale is a North American faunal stage in the North American Land Mammal Ages chronology (NALMA),Sanders, A.E., R.E. Weems, and L.B. Albright III (2009) Formalization of the mid- ...

. During that time ''P. dixi'' would have been a contemporary of other waterbirds including the horned grebe and the pied-billed grebe (''Podilymbus podiceps'').

References

{{Taxonbar, from=Q116008478 dixi Fossil taxa described in 1963 Birds described in 1963