Scaniacypselus
| Scaniacypselus | |
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Clade: | Strisores |
| Order: | Apodiformes |
| Family: | Apodidae |
| Genus: | †Scaniacypselus Harrison, 1984 |
| Type species | |
| Scaniacypselus wardi Harrison, 1984
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| Species | |
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Scaniacypselus is an extinct genus of basal
History and naming
The first remains of Scaniacypselus were recovered by D.J. Ward from the
The name derives from the Latin name of the region the type species was found in combined with "Cypselus", an old name of the common swift. The species name of Scaniacypselus wardi honors J.D. Ward who discovered the original fossil.[2]
Description
The type species, S. wardi, was noted to have had a short and stout
Although the type species is known from a single specimen, the second species, S. szarskii, is known from a multitude of individuals preserving not only skeletal elements but also soft tissue impressions. These specimens show several features clearly setting the genus apart from modern swifts. The crus dorsale fossae of the humerus is reduced and pneumatic fossae are missing in the fossils. Although this was first described in specimens from Messel, the same anatomy was also subsequently also recognized in fossils from France as well as the S. wardi holotype from Denmark. Scaniacypselus szarskii also differs notably in the proportions of the wings, with a relatively longer ulna and shorter carpometacarpus than its modern relatives. In this regard it more closely resembles
Wing shape is already indicated to have been relatively short by the osteology, which is confirmed by specimens preserving soft tissue such as feathers. These specimens show that the wings of Scaniacypselus weren't as long and narrow as in modern swifts of similar size.[1] The tail feathers of Scaniacypselus was only lightly forked.[3]
Phylogeny
When first described researchers noted that the taxon shares several key characteristics with crown group swifts, consequently placing it in the subfamily Apodinae.[2] The discovery of multiple additional specimens of S. szarskii however highlighted previously unknown features that set it apart from crown-group swifts. Mayr subsequently recovers Scaniacypselus not as a member of the family Apodinae, but instead as a more basal member of Apodidae.[1]
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Paleobiology
The broader wings of Scaniacypselus clearly show that the taxon is much less specialised than modern swifts. While true swifts are highly aerial animals that spend most their lifes in the air,[4] Scaniacypselus lived a much less airborne life. However their feeding range was likely much more extensive than that of the modern treeswifts, which are limited to hunting grounds close to the forest canopy.[1]
The feet of the bird also give clues to its lifestyle. In its hindlimb proportions Scaniacypselus is much more similar to treeswifts and hummingbirds as well as other perching birds than to true swifts. It is thought that the relatively reduced hindlimbs of swifts are linked to their highly aerial lifestyle, while the relative elongation of the tarsometatarsus is an adaptation to taking on a vertical position while roosting. The shortened toes and curved claws with strong flexing musculature would also aid in this behavior. Members of the genus Apus mark somewhat of a departure of those adaptations, their tarsometatarsus reducing in length likely due to the fact that out of all swift species they are the most aerial, rendering the adaptations for vertical roosting less significant (although the bone is still proportionally longer than in Scaniacypselus).[1]
The less derived anatomy of the legs together with the less specialised wings indicate that Scaniacypselus lived a different lifestyle compared to its modern relatives, roosting and nesting in a different manner. Specifically, the ability to perch like hummingbirds and treeswifts suggest that the animal was much more arboreal and nested in trees, spending much less time in flight than true swifts.[1]