Asteriornis
| Asteriornis Temporal range: LateMaastrichtian
| |
|---|---|
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| Skull in lateral view | |
Scientific classification
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Infraclass: | Neognathae |
| Clade: | Pangalloanserae |
| Genus: | †Asteriornis Fieldet al.2020 |
| Type species | |
| †Asteriornis maastrichtensis Fieldet al.2020
| |
Asteriornis( "Asteria'sbird "[1]) is an extinctgenusofbirdfrom theLate CretaceousofBelgiumwhich is known from a singlespecies,Asteriornis maastrichtensis.It was closely related to birds of the extant superorderGalloanseraesuch as chickens and ducks. Members of the genus were small, long-legged birds (~394 grams [13.9 oz])[1][2]that lived near the coastline and co-existed with more "primitive" types of birds such asIchthyornis.Asteriornisis one of the oldest-known birds irrefutably belonging to the groupNeornithes,which encompasses all modern birds. It possesses characteristics of bothgalliformes(chicken-like birds) andanseriformes(duck-like birds), indicating its position as a close relative of thelast common ancestorfor both groups.[1][3]
Asteriornismay shed light on why Neornithes were the onlydinosaursto survive theCretaceous–Paleogene extinction event.Its coexistence with non-neornithean birds such asIchthyornisimplies that competition was not a primary factor for the extinction of non-neornitheans, which resembled modern birds in most respects but died out with other non-avian dinosaurs. Small size,[4]a terrestrial lifestyle,[5]and a generalist diet[6]have all been inferred as ecological advantages possessed by early neornithes, allowing them to survive and diversify in the wake of the extinction.[3][7]Asteriornisfulfills these qualities, suggesting that such suspicions were justified.[1]Asteriornisis also evidence against a different hypothesis stating that modern birds originated from southern continents. This was supported by biogeographicancestral reconstructionsusingphylogenies[8]and the discovery ofVegavis(a possible neornithean from Antarctica),[9]butAsteriornis's presence in Europe suggests that modern birds may have been widespread in northern continents in their early evolution.[1]
Discovery and naming
[edit]Asteriornisis based on specimen NHMM 2013 008, held in theMaastricht Natural History Museum(Dutch:Natuurhistorisch Museum Maastricht), which consists of an almost complete skull and fragments of leg bones and aradius.It was retrieved from four blocks of sediment found at the CBR-Romontbos quarry nearEben-Emaelin theMaastricht FormationofBelgium,[1]and was first unearthed in 2000,[10]by amateur paleontologist Maarten van Dinther,[11]who donated it to the museum.[1]This geological formation is the namesake of theMaastrichtianstage, which was the last stage of theCretaceousperiod and theMesozoicera. It is dated to around 66.8 to 66.7 million years old,[12]less than a million years before the arrival of the asteroid that caused theCretaceous–Paleogene extinction event,killed off all non-avian dinosaurs (and many other animals), and began theCenozoicera.[1]
The genus name,Asteriornis,was constructed fromornis,theGreekword for bird,[13]and fromAsteria,atitanfromGreek mythology,who was associated with falling stars, and about whom there is a famous myth in which she transforms herself into aquail.TheAsteripart of genus name thus alludes to theChicxulub impactor(a "falling star" ), and also alludes to quails which are members of the galloanserans. The species nameA. maastrichtensisis named after theMaastricht Formation.[1]The researchers who discovered and described thefossilgaveAsteriornisthe nickname "Wonderchicken", which was picked up by various news outlets.[10][14]
Description
[edit]
The beak was slightly downcurved and lightweight. Unlike galloanserans, the beak did not have any specialized connections to the rest of the skull, nor a hooked tip. Instead its front tip was slightly rounded. The skull was narrowest over theorbits(eye sockets), where thefrontal boneswere incised by a V-shaped part of thenasal bones.The bones forming the jaw joint were very galloanseran-like. Thequadrate bone(the cranium's contribution to the jaw joint) connected to theskullroof via two pronounced knobs, which were adjacent to a third smaller knob, the tuberculum subcapitulare. Themandible(lower jaw) connected to the quadrate with a pair of sockets, and the rear end of the lower jaw had a large hooked rearward-facing retroarticular process as well as a smaller inward-facing medial process. All of these characteristics are considered unique to (or at least most common in) galloanserans.[1]
In some respects the skull seems more similar to galliform birds such as chickens and pheasants. These include unfused snout bones and nasal bones which fork in front of the eyes. In other respects it resembles anseriform birds such as ducks and geese. Such features include the hooked retroarticular process of the jaw and apostorbital process(the portion of bone forming the rear edge of the eye socket) which curves forward at its lower extent. These demonstrate a principle of evolution that animals close to the common ancestor of two groups share some similarities with each group.[1]
Theradiusfragment flattens and widens towards the wrist, where it possesses a large hooked bump. Leg bones are elongated and slender, similar in proportions and structure to modern ground-living birds. Thefemurhas well-developed muscle ridges and a large, angularmedial condyle.Thetibiotarsusis widest towards the knee, while thetarsometatarsusis thinner and covered with ridges.[1]
Classification
[edit]Aphylogeneticanalysis placedAsteriornisnear the base ofGalloanserae,an expansive superorder containing birds such as chickens, ducks, pheasants, and other types of fowl and gamebirds. The precise placement varied based on whether the analysis usedparsimonyorBayesianprotocol. Parsimony placed it as thesister taxonto Galloanserae, meaning that it was a distant relative of thelast common ancestorof chickens and ducks. Bayesian protocol instead placed it within Galloanserae, specifically as the sister taxon toGalliformes.This means that it was more closely related to chickens than to ducks, but also that was not a direct ancestor of modern chicken-like birds.[1]
ClassifyingAsteriornisas a relative of chickens and ducks means that it is unequivocally aneornithean.This is important because Neornithes originated at the last common ancestor of all living birds, and corresponds to the term "bird" as it refers to modern-day animals. Pre-neornithean birds such asIchthyornis,enantiornitheans,orArchaeopteryxgenerally resemble modern birds but retain primitive features such as teeth or wing claws.[3]Neornithean fossils are extremely rare from the Mesozoic age, and are generally fragmentary or poorly described. The oldest known neognath, specifically a stem-anseriform, is thepresbyornithidTeviornisfrom theNemegt FormationofMongoliaaround70million years ago.[15]Vegavisfrom the Late Cretaceous (~66.5 Ma) ofAntarcticawas originally described as a relative of ducks and geese,[9]but the classification ofvegaviidsis controversial and some paleontologists do not consider it a proper neornithean,[16]or at least not an anseriform or a galloanserine.[17][18]Asteriornisis based on diagnostic and well-preserved skull material and its status is less unstable, so it can be considered among the oldest known undisputed fossil of a modern-style neornithean bird.[1]
At least one study in 2021 has recoveredAsteriornisas apaleognath,albeit "with limited support".[19]Subsequent studies still supportAsterornisas a neornithean closely related to or within Galloanserae based on morphometric and phylogenetic analyses.[20][21]A 2024 cladistic analysis placedAsteriorniswithin the crown-group Galloanserae, specifically as astem-galliform,though reexaminations of its mandible suggested that it lacked a key galloanserine feature.[22]
References
[edit]- ^abcdefghijklmnField, Daniel J.; Benito, Juan; Chen, Albert; Jagt, John W. M.; Ksepka, Daniel T. (18 March 2020). "Late Cretaceous neornithine from Europe illuminates the origins of crown birds".Nature.579(7799): 397–401.doi:10.1038/s41586-020-2096-0.ISSN1476-4687.PMID32188952.S2CID212937591.
- ^Field, Daniel J.; Lynner, Colton; Brown, Christian; Darroch, Simon A. F. (2013-11-29)."Skeletal Correlates for Body Mass Estimation in Modern and Fossil Flying Birds".PLOS One.8(11): e82000.Bibcode:2013PLoSO...882000F.doi:10.1371/journal.pone.0082000.ISSN1932-6203.PMC3843728.PMID24312392.
- ^abcPadian, Kevin (18 March 2020). "Poultry through time".Nature.579(7799): 351–352.doi:10.1038/d41586-020-00766-2.PMID32188944.
- ^Berv, Jacob S.; Field, Daniel J. (2018-01-01)."Genomic Signature of an Avian Lilliput Effect across the K-Pg Extinction".Systematic Biology.67(1): 1–13.doi:10.1093/sysbio/syx064.ISSN1063-5157.PMC5837713.PMID28973546.
- ^Field, Daniel J.; Bercovici, Antoine; Berv, Jacob S.; Dunn, Regan; Fastovsky, David E.; Lyson, Tyler R.; Vajda, Vivi; Gauthier, Jacques A. (2018-06-04)."Early Evolution of Modern Birds Structured by Global Forest Collapse at the End-Cretaceous Mass Extinction".Current Biology.28(11): 1825–1831.e2.doi:10.1016/j.cub.2018.04.062.ISSN0960-9822.PMID29804807.
- ^Larson, Derek W.; Brown, Caleb M.; Evans, David C. (2016-05-23)."Dental Disparity and Ecological Stability in Bird-like Dinosaurs prior to the End-Cretaceous Mass Extinction".Current Biology.26(10): 1325–1333.doi:10.1016/j.cub.2016.03.039.ISSN0960-9822.PMID27112293.
- ^Ksepka, Daniel T.; Stidham, Thomas A.; Williamson, Thomas E. (2017-07-10)."Early Paleocene landbird supports rapid phylogenetic and morphological diversification of crown birds after the K–Pg mass extinction".Proceedings of the National Academy of Sciences.114(30): 8047–8052.Bibcode:2017PNAS..114.8047K.doi:10.1073/pnas.1700188114.ISSN0027-8424.PMC5544281.PMID28696285.
- ^Claramunt, Santiago; Cracraft, Joel (2015-12-01)."A new time tree reveals Earth history's imprint on the evolution of modern birds".Science Advances.1(11): e1501005.Bibcode:2015SciA....1E1005C.doi:10.1126/sciadv.1501005.ISSN2375-2548.PMC4730849.PMID26824065.
- ^abClarke, Julia A.; Tambussi, Claudia P.; Noriega, Jorge I.; Erickson, Gregory M.; Ketcham, Richard A. (20 January 2005)."Definitive fossil evidence for the extant avian radiation in the Cretaceous"(PDF).Nature.433(7023): 305–308.Bibcode:2005Natur.433..305C.doi:10.1038/nature03150.ISSN1476-4687.PMID15662422.S2CID4354309.
- ^abGiamio, Cara (March 18, 2020)."What to Name the Oldest Modern Bird Fossil? Wonderchicken".The New York Times.Archivedfrom the original on March 19, 2020.RetrievedMarch 19,2020.
- ^"Oldest fossil 'Wonderchicken' found at Maastricht by Lab Technician Maarten van Dinther".
- ^Keutgen, Norbert (December 2018)."A bioclast-based astronomical timescale for the Maastrichtian in the type area (southeast Netherlands, northeast Belgium) and stratigraphic implications: the legacy of P.J. Felder".Netherlands Journal of Geosciences.97(4): 229–260.doi:10.1017/njg.2018.15.ISSN0016-7746.
- ^ὄρνις.Liddell, Henry George;Scott, Robert;A Greek–English Lexiconat thePerseus Project.
- ^KOUMOUNDOUROS, Tessa (March 20, 2020)."This 'Wonderchicken' Could Be The Oldest Modern Bird Fossil, And a True Survivor".ScienceAlert.com.Archivedfrom the original on March 20, 2020.RetrievedMarch 20,2020.
- ^Marjanović, D. (2021)."The Making of Calibration Sausage Exemplified by Recalibrating the Transcriptomic Timetree of Jawed Vertebrates".Frontiers in Genetics.12.521693.doi:10.3389/fgene.2021.521693.PMC8149952.PMID34054911.
- ^Mayr, G.; De Pietri, V.L.; Scofield, R.P.; Worthy, T.H. (2018). "On the taxonomic composition and phylogenetic affinities of the recently proposed clade Vegaviidae Agnolín et al., 2017 ‒ neornithine birds from the Upper Cretaceous of the Southern Hemisphere)".Cretaceous Research.86:178–185.doi:10.1016/j.cretres.2018.02.013.hdl:2328/37887.S2CID134876425.
- ^Acosta Hospitaleche C, Worthy TH (2021). "New data on theVegavis iaaiholotype from the Maastrichtian of Antarctica ".Cretaceous Research.124.104818.Bibcode:2021CrRes.12404818A.doi:10.1016/j.cretres.2021.104818.S2CID233703816.
- ^Álvarez-Herrera, G. P.; Rozadilla, S.; Agnolín, F. L.; Novas, F. E. (2024). "Jaw anatomy ofVegavis iaai(Clarke et al., 2005) from the Late Cretaceous Antarctica, and its phylogenetic implications ".Geobios.83:11–20.doi:10.1016/j.geobios.2023.03.004.S2CID259955013.
- ^Torres, Christopher R.; Norell, Mark A.; Clarke, Julia A. (2021)."Bird neurocranial and body mass evolution across the end-Cretaceous mass extinction: The avian brain shape left other dinosaurs behind".Science Advances.7(31).Bibcode:2021SciA....7.7099T.doi:10.1126/sciadv.abg7099.PMC8324052.PMID34330706.
- ^Kuo, Pei-Chen; Benson, Roger B. J.; Field, Daniel J. (2023)."The influence of fossils in macroevolutionary analyses of 3D geometric morphometric data: A case study of galloanseran quadrates".Journal of Morphology.284(6): e21594.doi:10.1002/jmor.21594.PMID37183494.S2CID258367829.
- ^Brocklehurst, N.; Field, D. J. (2024)."Tip dating and Bayes factors provide insight into the divergences of crown bird clades across the end-Cretaceous mass extinction".Proceedings of the Royal Society B: Biological Sciences.291(2016). 20232618.doi:10.1098/rspb.2023.2618.PMC10865003.PMID38351798.
- ^Crane, A.; Benito, J.; Chen, A.; Musser, G.; Torres, C. R.; Clarke, J. A.; Lautenschlager, S.; Ksepka, D. T.; Field, D. J. (2024)."Taphonomic damage obfuscates interpretation of the retroarticular region of theAsteriornismandible ".Geobios.doi:10.1016/j.geobios.2024.03.003.
