| Limenavis | |
|---|---|
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | Theropoda |
| Clade: | Avialae |
| Clade: | Ornithuromorpha |
| Clade: | Ornithurae |
| Genus: | †Limenavis Clarke &Chiappe, 2001 |
| Species: | †L. patagonica |
| Binomial name | |
| †Limenavis patagonica Clarke & Chiappe, 2001 | |
Limenavis is agenus ofornithurandinosaurs from the LateCretaceous. It lived about 70 million years ago, around theCampanian-Maastrichtian boundary. Known from several broken bones, the remains of the only knownspeciesLimenavis patagonica were found in rocks of the "lower member" of theAllen Formation atSalitral Moreno, 20 km south ofGeneral Roca, Río Negro (Argentina).[1] It is one of the closest relatives, in the fossil record, of the modernbirds.[2]
Of all thestem-birds known to date, this species is among those closest to the common ancestor of all living birds. Itsgeneric name pays tribute to this fact:Limenavis, meaning "bird of the threshold" or "limit-bird", is derived fromLatinlimen ("threshold") +avis ("bird"). Thespecific namepatagonica refers to the specimen'sPatagonian provenance.
The relationships ofLimenavis have been difficult to determine. Analyses published in 2001 and 2002 byJulia Clarke and Luis Chiappe foundLimenavis to be a member ofCarinatae more advanced thanIchthyornis but not a member of the modern bird groupNeornithes.[3][4] A 2013 analysis by O'Connor and colleagues found it to be slightly more primitive thanIchthyornis.[5]
It has been suggested that some features link it withpaleognath birds, perhaps related to the ancestors oftinamous orrheas.[6] Though such birds must have existed by that time already, and most likely at least tinamou ancestors (basal Tinamiformes) did live inSouth America by the Late Cretaceous, tinamous proper (Tinamidae) are only known with certainty since theMiocene.[7]
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