Praemegaceros cazioti

''Praemegaceros'' is an extinct genus of deer, known from the Pleistocene and Holocene of Western Eurasia. ''Praemegaceros'' is considered to be a genus of "giant deer", with many species having an estimated body mass of around , considerably larger than most living deer.

The genus contains the subgenera ''Praemegaceros,'' ''Orthogonoceros'' and ''Nesoleipoceros''. It has sometimes been synonymised with ''Megaloceros'' and ''Megaceroides'', but is regarded as a distinct genus by most studies. Some authors have considered the genus closely related to ''Megaloceros'', but this has been disputed by others.

The earliest species like ''P. obscurus'' and ''P. verticornis'' appeared in Europe between 2 and 1.5 million years ago. The genus was widely distributed across Europe, West and Central Asia during the Early-Middle Pleistocene, with fossils having been discovered in France, Georgia, Germany, England, Greece, Israel, Italy, Romania, Russia Spain, Syria, and Tajikistan. The genus was extinct in mainland Europe and Asia by end of the Middle Pleistocene. An insular species, ''P. cazioti'' survived into the Late Pleistocene and Holocene in isolation on the Sardinia-Corsica archipelago until around 5500 BCE.

Taxonomy

''Praemegaceros'' was first described as a subgenus of ''Cervus'' by Portis in 1920, to include ''Cervus'' (''Praemegaceros'') ''dawkinsi.'' Kalkhe in 1956 named ''Orthogonoceros'' with the type species of ''Orthogonoceros'' (previously ''Cervus'') ''verticornis.'' Kalkhe in 1965 recognised that these genera were synonyms, with ''Praemegaceros'' having priority. Radulesco & Samson in 1967 designated ''P.'' ''dawkinsi'' as the type species of the genus, while also naming the new genera ''Allocaenelaphus, Psecupsoceros,'' and ''Nesoleipoceros'' which are now recognised as synonyms of the genus. Some authors have used the genus "''Megaceroides''" to include the species usually placed in ''Praemegaceros'', but the type species of ''Megaceroides'', the North African ''Megaceroides algericus'' is morphologically distinct from ''Praemegaceros''. ''Praemegaceros'' is widely agreed to be belong to the subfamily Cervinae. ''Praemegaceros'' is considered a genus of "giant deer", and has often been placed in the tribe Megacerini, alongside genera like ''Megaloceros'' and ''Sinomegaceros,'' though other authors have disputed the close relationship between ''Praemegaceros'' and ''Megaloceros'', alternatively suggesting that the two genera obtained their large size independently, and instead propose a close relationship of ''Praemegaceros'' with the genus ''Eucladoceros''.

Classification according to Croitor, 2018.

Subgenus ''Orthogonoceros''

''Praemegaceros pliotarandoides''

Known from the late Early Pleistocene and Middle Pleistocene of Italy, North Greece, Moldova, South Ukraine and the Azov Sea Region. It was named by De Alessandri in 1903 for remains found in North Italy. ''Psekupsoceros orientalis'' is a junior synonym of the taxon. Estimated body mass of around .

''Praemegaceros verticornis''

Named by William Boyd Dawkins in 1872 on the basis of a partial antler from the Cromer Forest Bed. Croitor suggests that ''Cervus belgrandi'' is a junior synonym. Known from late Early Pleistocene to Middle Pleistocene localities in England, Spain, France, Germany and Italy. Estimated body mass of around .

Isotopic analysis of specimens from the Early Pleistocene (about 1.6 million years ago) Venta Micena locality of southern Spain, suggests that at this locality the species was almost exclusively browsing (feeding on leaves and twigs of high growing plants like shrubs and trees) in forested environments.

Subgenus ''Nesoleipoceros''

''Praemegaceros solilhacus''

The species was named by Robert in 1930 for remains from Soleilhac, an early Middle Pleistocene site located in the Massif Central, France. The neotype specimen consists of a partial left frontal with an attached partial antler. The morphology of the preserved antler strongly resembles that of ''P. cazioti,'' which suggests a close relationship. Other known sites are from the early Middle Pleistocene of France, Germany, Italy, South Russia and Moldova. This taxon is suggested to be the largest species of ''Praemegaceros'', with an estimated mass of . The taxon appears to have been extinct by the late Middle Pleistocene.

''Praemegaceros sardous–Praemegaceros cazioti''

Endemic to the Sardinia-Corsica archipelago from the late Middle Pleistocene to the Early Holocene, the ancestor of ''P. cazioti'' appears to have dispersed to the islands during the Middle Pleistocene, with the earliest well dated records of ''Praemegaceros'' at Su Fossu de Cannas in Sardinia being over 450,000 years in age. Other early remains of the genus in Sardinia are referred to the species ''P. sardus/sardous''. The oldest remains assigned to ''P. cazioti'' date to approximately 300,000 years ago. ''P. cazioti'' is smaller than ''P. sardus'', being slightly larger than a fallow deer, with an estimated body mass of around , exhibiting an over 75% size reduction from its presumed mainland ancestor ''Praemegaceros solilhacus,'' an example of insular dwarfism. The cranial morphology appears to be unaffected by the insular dwarfism. Two chronologically separated subspecies are known, which are suggested to be chronospecies. ''P. cazioti cazioti'' dates to the late Middle Pleistocene and Late Pleistocene and is characterised by smaller brachyodont teeth and ''P. cazioti algarensis'' from the end of the Late Pleistocene is larger than ''P. cazioti cazioti'' and is characterised by large mesodont upper cheek teeth, and a long premolar series, which are suggested to be adaptions for a grazing diet. The youngest date for ''P. cazioti'' is around 5500 BCE, making it the latest surviving ''Praemegaceros'' species.

Subgenus ''Praemegaceros''

''Praemegaceros obscurus''

Known from the late Villafranchian of Europe (including Central Italy, Central Romania and Moldova) and the Near East, extending from the Cromer Forest Bed in England to Ubeidiya, Israel, Dmanisi, Georgia and the Azov region, Russia. Croitor suggests an origin in South Asia for this species, descended from taxa possibly referrable to '' Panolia sp.'' from the Siwaliks. Estimated body mass of around .

''Praemegaceros dawkinsi''

Named in 1882 from remains from the Middle Pleistocene Cromer Forest Bed in Norfolk by Edwin Tulley Newton which were originally described in 1872 as belonging to ''P. verticornis'' by William Boyd Dawkins. The body mass is estimated to be around , with a mesodont dentition. Croitor suggests that because the pedicles (base of the antlers) are robust and similar to those of giant deer, that ''P. dawkinsi'' represents a dwarfed form. The species is considered to be endemic to Britain, with the antler morphology simplified relative to other ''Praemegaceros'' species.

''Praemegaceros mosbachensis''

Named by Wolfgang Soergel in 1927 for the species found in the lowest level of the Middle Pleistocene Mosbach locality in Germany. It was included in the “verticornis” group of Azzaroli's 1953 classification. It has been suggested to a be synonym of ''P. verticornis.'' However, Croitor suggests that these similarities are the result of parallel evolution, and proposes that ''P. mosbachensis'' represents an intermediate form between ''P. obscurus'' and ''P. dawkinsi.''

Ecology

During the Early-Middle Pleistocene, mainland species of ''Praemegaceros'' are suggested to have been preyed upon by the sabertooth cats ''Megantereon'' and ''Homotherium'', and the "European jaguar" ''Panthera gombaszoegensis''.''''

References

{{Taxonbar, from=Q25095511

Prehistoric deer
Pleistocene Artiodactyla
Pleistocene genus extinctions
Piacenzian first appearances
Pliocene Artiodactyla
Prehistoric Artiodactyla genera