Eoalulavis
| Eoalulavis | |
|---|---|
| |
| Life restoration. | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | Theropoda |
| Clade: | Avialae |
| Clade: | †Enantiornithes |
| Genus: | †Eoalulavis Sanz et al., 1996 |
| Species: | †E. hoyasi
|
| Binomial name | |
| †Eoalulavis hoyasi Sanz et al., 1996
| |
Eoalulavis (from the Ancient Greek:
Discovery
Its remains came from the
theropods[3] or insect wings[4]). Most of the osteological features of the holotype became apparent only after its acid preparation and transference to a resin cast.[2]
Description
Size
According to its initial description, E. hoyasi was roughly the size of a european goldfinch (Carduelis carduelis), with the bony elements of its wings approximately 17 centimeters (7 inches) in length.[1] Later studies estimated that it had a weight of approximately 45 grams (1.6 ounces) and total wingspan (including feathers) of about 26 centimeters (10 inches), giving it proportions similar to those of a common kingfisher (Alcedo atthis).[5]
Characteristics
One of the most unusual features of this genus lies in the shape of its bony sternum (breastplate). While most early birds had wide sternums, Eoalulavis had a very thin one, with an expanded front end tapering to a point as well as a rear tip with outward-pointing extensions. This form has been described as "spear-shaped" or "fish-shaped" by some.[1][2]
The morphology of the forelimb in Eoalulavis is remarkably primitive compared with that of other genera of
At the time of its discovery, it was the earliest bird known to possess an
modern birds along with their fossil counterparts, suggest that the development of the alula, and the flight capabilities that it implies, occur early in the avian evolution, presumably in the base of Ornithothoraces.[2][9]
Paleobiology and Paleoecology
Flight
The presence of
taxa.[6] Its hindlimb morphology remain uncertain as no material of this kind referable to the genus has been found to date. A 2018 study analyzed the proportions of Eoalulavis and Concornis to determine the optimal flight pattern for those genera. The study found that they likely engaged in bounding flight, a form of flight popular among modern small and short-winged birds. A bird engaging in bounding flight alternates between upward-thrusting flaps and short dives with folded wings. The study also found that they were capable of continuous flapping flight, but were likely unable to glide due to having a high body mass to wingspan ratio. The study concluded that Eolalulavis, Concornis, and likely many other enantiornitheans alternated between the fast bounding flight and the slower but more efficient flapping flight depending on the circumstances, similar to modern songbirds and woodpeckers.[5]
Diet
The
invertebrates in a similar way of modern turnstones.[4]
Environment
The locality of
Concornis lacustris.[12] Eoalulavis hoyasi is believed to be the most linked to a semi-aquatic environment of the three.[12]
Classification
The
monophyletic group of derived Enantiornithes. Nevertheless, this concrete grouping has not a high statistical support and the enantiornithean status of Liaoningornis remains currently controversial.[14][15]
Eoalulavis hoyasi presents numerous
coracoids.[2]
References
- ^ doi:10.1038/382442a0(HTML abstract)
- ^ a b c d e f g Sanz, J., Pérez-Moreno, B., Chiappe, L., Buscalioni, A., Chiappe, L. & Witmer, L. (2002): "The birds from the lower Cretaceous of las hoyas (Province of Cuenca, Spain)", Mesozoic Birds: Above the Heads of the Dinosaurs.University of California Press, Berkeley, , pp. 209-229.
- ^ a b Briggs, D.E., Wilby, P.R., Pérez-Moreno, B.P., Sanz, J.L. & Fregenal-Martínez, M. (1997): "The mineralization of dinosaur soft tissue in the Lower Cretaceous of Las Hoyas, Spain", Journal of the Geological Society, vol. 154, no. 4, pp. 587-588.
- ^ a b c Fregenal-martínez, M. & Buscalioni, A. (2010): "A holistic approach to the palaeoecology of Las Hoyas Konservat-Lagerstätte (La Huérguina Formation, Lower Cretaceous, Iberian Ranges, Spain)", Journal of Iberian Geology, vol. 36, no. 2, pp. 297-326.
- ^ ISSN 1475-4983.
- ^ a b c d e O’Connor, J., Chiappe, L.M. & Bell, A. (2011): "Pre-modern birds: avian divergences in the Mesozoic", Living dinosaurs: the evolutionary history of modern birds.Edited by GJ Dyke, and G.Kaiser.John Wiley and Sons Ltd., London, UK, , pp. 39-114.
- ^ Zhang, F. & Zhou, Z. (2000): "A primitive enantiornithine bird and the origin of feathers", Science, vol. 290, no. 5498, pp. 1955-1959.
- ^ Zhou, Z., Chiappe, L.M. & Zhang, F. (2005): "Anatomy of the Early Cretaceous bird Eoenantiornis buhleri (Aves: Enantiornithes) from China", Canadian Journal of Earth Sciences, vol. 42, no. 7, pp. 1331-1338.
- ^ a b Chiappe, L.M.(2007): Glorified dinosaurs: the origin and early evolution of birds, John Wiley.
- ^ Longrich, N.R., Vinther, J., Meng, Q., Li, Q. & Russell, A.P. (2012): "Primitive Wing Feather Arrangement in Archaeopteryx lithographica and Anchiornis huxleyi", Current Biology, .
- ^ Sanz, J., Bonapartet, J. & Lacasa, A. (1988): "Unusual early cretaceous birds from Spain", Nature, vol. 331, no. 6155, pp. 433-435.
- ^ a b Sanz, J. & Buscalioni, A. (1992): "A new bird from the Early Cretaceous of Las Hoyas, Spain, and the early radiation of bird s", Palaeontology, vol. 35, no. 4, pp. 829-845.
- ^ a b c O’Connor, J.K., Zhang, Y., Chiappe, L.M., Meng, Q., Quanguo, L. & Di, L. (2013): "A new enantiornithine from the Yixian Formation with the first recognized avian enamel specialization", Journal of Vertebrate Paleontology, vol. 33, no. 1, pp. 1-12.
- ^ Zhou, Z. (2002): "A new and primitive enantiornithine bird from the Early Cretaceous of China", Journal of Vertebrate Paleontology, vol. 22, no. 1, pp. 49-57.
- ^ O’Connor, J. (2012): "A revised look at Liaoningornis longidigitrus (Aves)", Vertebrata PalAsiatica, vol. 5, no. 1, pp. 25-37.
- ^ Chiappe, L.M., Walker, C.A., Chiappe, L. & Witmer, L. (2002): "Skeletal morphology and systematics of the Cretaceous Euenantiornithes (Ornithothoraces: Enantiornithes)", Mesozoic birds: above the heads of dinosaurs, , pp. 240-267.