''Miobaptus'' is a fossil genus of

grebe Grebes () are aquatic diving birds in the order Podicipediformes . Grebes are widely distributed freshwater birds, with some species also found in marine habitats during migration and winter. Some flightless species exist as well, most notably ...

that is known from several specimens collected from Czechia and Lake Baikal dating from the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was prece ...

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...

. Considered to be one of the most primitive genus of grebes, the anatomy of ''Miobaptus'' suggests it was less adapted for the aquatic mode of life than modern grebes, but had better flight maneuverablity.

History

The holotype species ''M. walteri'' was collected from

Dolnice Dolnice (, german: Deunitze) is a former settlement in central Slovenia in the northwest part of the capital Ljubljana. It belongs to the Dravlje District of the City Municipality of Ljubljana. It is part of the traditional region of Upper Carniol ...

and described by Švec (1982). He would later described more specimens of the species from

Bohemia Bohemia ( ; cs, Čechy ; ; hsb, Čěska; szl, Czechy) is the westernmost and largest historical region of the Czech Republic. Bohemia can also refer to a wider area consisting of the historical Lands of the Bohemian Crown ruled by the Bohem ...

in 1984. A second species ''M. huzhiricus'' was described by Zelenkov (2015) from specimens collected from

Olkhon Island Olkhon ( rus, Ольхо́н, also transliterated as Olchon; bua, Ойхон, ''Oikhon'') is the third-largest lake island in the world. It is by far the largest island in Lake Baikal in eastern Siberia, with an area of . Structurally, it const ...

Description

The distal part in the humeri of ''Miobaptus'' is different from extant grebes as the surface is flat and overall the wingbones more elongated. In contrast the distal ends in the humeri of extant grebes the surfaces is more concave, and overall they have much shorter wingbones.

Classification

''Miobaptus'' is placed basally in the phylogenetic tree of grebes where similarities have been made between this genus and

Palaelodidae Palaelodidae is a family of extinct birds in the group Phoenicopteriformes, which today is represented only by the flamingos. They have been described as "swimming flamingos." They can be considered evolutionarily, and ecologically, intermediate ...

. The palaelodids is an extinct family of

Phoenicopteriformes Phoenicopteriformes is a group of water birds which comprises flamingos and their extinct relatives. Flamingos (Phoenicopteriformes) and the closely related grebes ( Podicipedidae) are contained in the parent clade Mirandornithes. Fossil rec ...

where they have been suggested to be the transitional form between

flamingo Flamingos or flamingoes are a type of Wader, wading bird in the Family (biology), family Phoenicopteridae, which is the only extant family in the order Phoenicopteriformes. There are four flamingo species distributed throughout the Americas ...

s and grebes. Both ''Miobaptus'' and the palaelodids share several features in the

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

and

coracoid A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is prese ...

. Therefore while ''Miobaptus'' is similar to ''Tachybaptus'' there are some differences and any similarity between the two is likely due to

plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and ...

features.

Paleobiology

''M. walteri'' is known from the Aquitanian stage of the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

while ''M. huzhiricus'' is from the boundary line between the

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

and

Langhian The Langhian is, in the ICS geologic timescale, an age or stage in the middle Miocene Epoch/Series. It spans the time between 15.97 ± 0.05 Ma and 13.65 ± 0.05 Ma (million years ago) during the Middle Miocene.GeoWhen (2007) The Langhian was a ...

stages. The presence of this genus in both Europe and Asia at this time is significant as it shows at this time grebes were already spreading across the globe, as well as how the avifaunas were being established to their present in Eurasia. Based on their anatomy it shows that ''Miobaptus'' was much better capable at flying than modern grebes (though it was not as specialized in being aquatic).

References

{{Taxonbar, from=Q107342026 Podicipediformes Prehistoric bird genera