Topic
Limnofregata
About: Limnofregata is a research topic. Over the lifetime, 2 publications have been published within this topic receiving 30 citations.
Papers
TL;DR: The presence of early pelecaniform bird lineages in limnic ecosystems prior to their known occurrences in marine deposits/habitats appears to indicate that some clades of peleCANiform birds may have undergone an evolutionary transition from freshwater to marine habitats in a pattern reminiscent of what has been suggested during the evolution of pinnipeds or that their palaeoecology included broader niches ranging across a variety of aquatic habitats.
Abstract: A humerus and a coracoid from the Early Eocene Wasatch Formation in the Washakie Basin of south-western Wyoming are the oldest materials (by ~2 million years) of the pelecaniform Limnofregata (Aves) and represent a new large species, Limnofregata hutchisoni sp. nov. This fossil is the oldest known member of the frigatebird lineage. Other than its large size relative to Limnofregata azygosternon and L. hasegawai, the new material is very similar morphologically to other known Limnofregata specimens. The size of this new species is comparable to the largest living species (e.g. Fregata minor and Fregata magnifiscens) and much larger than the two described species of Limnofregata. This fossil indicates that the hard minimum date previously advocated for molecular calibration of the split between Fregatidae and Suloidea is an underestimate by approximately two million years. The presence of early pelecaniform bird lineages (represented by Limnofregata and Masillastega) in limnic ecosystems prior to their known occurrences in marine deposits/habitats appears to indicate that some clades of pelecaniform birds may have undergone an evolutionary transition from freshwater to marine habitats in a pattern reminiscent of what has been suggested during the evolution of pinnipeds or that their palaeoecology included broader niches ranging across a variety of aquatic habitats. That transition in habitat occupation and the origin of many of the characteristic biological aspects present in the crown frigatebird clade likely occurred during a significant temporal gap (> 45 million years) in the fossil record of the frigatebird lineage after these earliest occurrences in the Early Eocene and before the oldest records of the extant Fregata species in the Pleistocene.
9 citations
TL;DR: Two skulls with mandibles and a partial postcranial skeleton are described as a new species, Limnofregata hasegawai, characterized by much larger size and a proportionately longer bill.
Abstract: Four additional specimens from the Green River Formation of Wyoming are referred to the Eocene frigatebird Limnofregata azygosternon Olson, originally described from a nearly complete skeleton and two partial paratypes. Two skulls with mandibles and a partial postcranial skeleton are described as a new species, Limnofregata hasegawai, characterized by much larger size and a proportionately longer bill. One of the referred specimens of L. azygosternon is from Eocene Lake Gosiute, whereas all of the other specimens of Limnofregata are from Fossil Lake. The species of Limnofregata would have taken advantage of frequent periodic dieoffs of fish in the Green River lakes. Geological and climatic factors that may have influenced the paleoecology, distribution, and size variation in frigatebirds in the Cenozoic are reviewed.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2015 | 1 |
| 2005 | 1 |