''Coua berthae'' is an extinct species of

coua Couas are large, mostly terrestrial birds of the cuckoo family, endemic to the island of Madagascar. Couas are reminiscent of African turacos when walking along tree branches, and they likewise feature brightly coloured bare skin around the eyes ...

, a large, mostly terrestrial bird in the cuckoo family, from

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. It was the largest member of its genus, living or extinct. It was named in honour of the Malagasy zoologist Berthe Rakotosamimanana.

Discovery and naming

Alfred Grandidier Alfred Grandidier (20 December 1836 – 13 September 1921) was a French naturalist and explorer. From a very wealthy family, at the age of 20, he and his brother, Ernest Grandidier (1833–1912), undertook a voyage around the world. At first ...

discovered a complete

tarsometatarsus The tarsometatarsus is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) and meta ...

at Apasambazimba as early as 1911. This bone is in the Academie Malgache and is now classified as a paratype. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, a left half of the pelvis, was brought to light in 1983 in the Grotte d'Anjohibe near Andranoboka. It is named after the Malagasy primatologist and palaeontologist, Bertha Rakotosamimanana.

Description

Due to the length of the pelvis half of and the tarsometatarsus of , it is assumed that ''Coua berthae'' represented the largest type of silk cuckoo. An estimated minimum weight of was calculated from the comparison of the basin lengths of four recent types of silk cuckoo using linear regression. This estimated weight is twice that of '' Coua gigas'' - the largest of the living couas. Given that all silk cuckoo species have proportionally small wing bones, it has been assumed that ''Coua berthae'' was not a good flyer.

Extinction

''Coua berthae'' is known only from fossilized remains from the Holocene period; the exact time of extinction and the cause are unknown. Deforestation could have been a contributing factor to its extinction.

References

{{Taxonbar, from=Q1136862 berthae Extinct birds of Madagascar Holocene extinctions Birds described in 1993