Vorona
Encyclopedia
Vorona is a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of prehistoric bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s. It was described from fossils found in a Maevarano Formation
Maevarano Formation
The Maevarano Formation is an Upper Cretaceous sedimentary rock formation found in the Mahajanga Province of northwestern Madagascar. It is most likely Maastrichtian in age, and records a seasonal, semiarid environment with rivers that had greatly varying discharges...

 quarry near the village of Berivotra, Mahajanga Province
Mahajanga Province
Mahajanga is a former province of Madagascar with an area of 150,023 km². It had a population of 1,896,000 . Its capital was Mahajanga.Except for Fianarantsoa, Mahajanga Province bordered all of the country's other provinces:...

, Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

. The age is Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...

, probably Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...

 (70.6–83.5 mya). V. berivotrensis is known from scattered remains, possibly from a single individual (UA
University of Antananarivo
University of Antananarivo is the primary public university of Madagascar, located in the capital Antananarivo.The school traces its founding to 16 December 1955 and the formation of the Institute for Advanced Studies in Antananarivo. It quickly established itself as the main center for higher...

 8651 and FMNH
Field Museum of Natural History
The Field Museum of Natural History is located in Chicago, Illinois, USA. It sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex known as the Museum Campus Chicago...

 PA715).

The phylogenic affiliation of Vorona is hard to determine due to the fragmentary nature of the remains, mainly because the fossil shows a mix of primitive avian features as well as some that seem very modern. Vorona might be a primitive ornithuromorph.

Vorona is sometimes confused with the dromaeosaur Rahonavis ostromi, a fossil of which was found in the same location. This confusion has led to the common misconception that Vorona had a deinonychosaur-like sickle claw on each foot.
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