Antarcticavis
Extinct Antarctic bird of uncertain evolutionary relationships.
Antarcticavis, whose name translates to "Antarctic bird," is an extinct bird genus whose evolutionary relationships are unclear. Scientists know it from a partial skeleton found in Antarctica's Snow Hill Island Formation. The only species, Antarcticavis capelambensis, was first announced in 2019, though the formal naming paper appeared in 2020. The holotype specimen (SDSM 78147) includes two thoracic vertebrae, the keel of the sternum, the right coracoid and shoulder blade, the sternal part of the left coracoid, both upper arm bones (the right complete, the left partial), the proximal ends of the right ulna and both left ulna and radius (still joined), the proximal parts of both right and left carpometacarpi plus the distal left carpometacarpus, the synsacrum, both thigh bones, the proximal right tibiotarsus, the distal ends of both tibiotarsi, and the proximal right tarsometatarsus. A later detailed study of the polar section modulus of its bones placed it in the same morphospace as amphibious seabirds, closest to the common merganser (Mergus merganser) and the great black-backed gull (Larus marinus). In their 2025 description of the bird Pujatopouli, researchers Irazoqui and colleagues found Antarcticavis in different positions depending on the analytical matrix used—either as a basal member of, and possibly a sister taxon to, the clade Neornithes, or within the clade Aequornithes—and concluded that its taxonomic placement remains uncertain.
Quick Facts
- Taxon
- Antarcticavis
- Type Species
- Antarcticavis capelambensis
- Type Species Authority
- Cordes-Person et al., 2020
Facts from the source article.
Lore & Background
Antarcticavis is known from a partial skeleton designated SDSM 78147, which includes two thoracic vertebrae, the sternum keel, the right coracoid and shoulder blade, the sternal part of the left coracoid, the right upper arm, parts of the left upper arm, the proximal right ulna, the proximal left ulna and radius (articulated), the proximal right carpometacarpus, the proximal left carpometacarpus, the distal left carpometacarpus, the synsacrum, the right and left thighs, the proximal right tibiotarsus, the right and left distal tibiotarsus, and the proximal right tarsometatarsus. The genus was announced in 2019, with the final naming article published in 2020.
Reader's Guide
Antarcticavis is significant as a fossil bird from Antarctica, a region that provides critical insights into avian evolution in high-latitude environments. Its phylogenetic placement remains problematic, as detailed in a 2025 study by Irazoqui and colleagues describing Pujatopouli. Using different matrices, they recovered Antarcticavis either at a basal position within and possibly a sister taxon of the clade Neornithes, or within the clade Aequornithes. This uncertainty highlights the challenges of classifying fragmentary fossils. More recent analysis of the polar section modulus of its bones placed it in amphibious-seabird morphospaces, closest to Mergus merganser and Larus marinus. Thus, Antarcticavis contributes to understanding the morphological diversity and ecological roles of ancient Antarctic birds, though its exact evolutionary relationships remain unresolved.
Did You Know?
- Antarcticavis means 'Antarctic bird'.
- The holotype, SDSM 78147, includes parts of the vertebrae, sternum, coracoids, upper arm bones, ulnae, radius, carpometacarpi, synsacrum, thighs, tibiotarsi, and tarsometatarsus.
- In a 2025 study, Antarcticavis was recovered either as a basal member of Neornithes or within Aequornithes, depending on the matrix used.
More in Fossils of Antarctica 1-24
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