''Eogranivora'' is a

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

genus, belonging to the

Ornithuromorpha Euornithes (from Greek ' meaning "true birds") is a natural group which includes the most recent common ancestor of all avialans closer to modern birds than to ''Sinornis''. Description Clarke ''et al''. (2006) found that the most primitive know ...

, that lived in the area of present-day China during the Early Cretaceous. Its

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

is ''Eogranivora edentulata''.Zheng X., O’Connor J.K., Wang X., Wang Y., Zhou Z. 2018. "Reinterpretation of a previously described Jehol bird clarifies early trophic evolution in the Ornithuromorpha". ''Proceedings of the Royal Society B'' 285: 20172494 In 2011, a bird

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

, specimen STM35-3 found at Dawangzhangzi, was referred to '' Hongshanornis''.Zheng X-T., Martin L.D., Zhou Z-H., Burnham D.A., Zhang F-C., Miao D. 2011 "Fossil evidence of avian crops from the Early Cretaceous of China". ''Proceedings of the National Academy of Sciences. USA'' 108: 15 904–15 907 Subsequently, that genus was proven to possess teeth, while STM35-3 is toothless. Additional research showed that the latter represented a species new to science. In 2018, the type species ''Eogranivora edentulata'' was named and described by Zheng Xiaoting, Jingmai Kathleen O'Connor, Wang Xiaoli, Wang Yan and

Zhou Zhonghe Zhou Zhonghe (; born 19 January 1965 in Jiangdu, Jiangsu province) is a Chinese palaeontologist. He described the ancient bird ''Confuciusornis''.. Zhou graduated from Nanjing University and earned a Ph.D. in Biology in 1999 from the University o ...

. The generic name combines a Greek ''eos'', "dawn", with Neolatin ''granivora'', "group of seed eaters", in reference to the species being the oldest known seed-eating ornithuromorph bird. The specific name means "toothless" in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

. ''Eogranivora'' was the first fossil bird species to have been named in 2018. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

, STM35-3, was discovered in a layer of the

Yixian Formation The Yixian Formation (; formerly transcribed as Yihsien Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the late Barremian and early Aptian stages of the Early Cretaceous. It is known for its exq ...

dating from the early Aptian, at about 125 million years old. It consists of a nearly complete skeleton with skull, compressed on a plate and counterplate. The splitting of the slabs damaged the bones of the fossil. It is largely articulated. Extensive but vague remains of the plumage have been preserved as well as a

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydropon ...

with seeds and a stomach with

gastrolith A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In oth ...

s. ''Eogranivora'' is a medium-sized basal ornithuromorph. The describing authors indicated a distinguishing combination of traits, in themselves not unique. Both upper and lower jaws are toothless. The front of the lower jaws is fused into a symphysis for a fifth of their lengths. The coracoid does not have a clear process to contact the side of the breastbone. The outer and intermediate rear processes of the breastbone are thin and project to the rear to the same level. The central xiphoid process at the rear of the breastbone is V-shaped. The first finger is short but robust. The

pubic bone In vertebrates, the pubic region ( la, pubis) is the most forward-facing ( ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ...

at its top has a triangular process pointing to above and the inside, at a third of its shaft length. The first

metatarsal The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the me ...

and the first toe are completely lacking. ''Eogranivora'' was placed in the Ornithuromorpha, in a rather basal position in a

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...

, below the Hongshanornithidae but above '' Archaeorhynchus''. The combination of a crop with seeds—the first time for a Mesozoic ornithuromorph—a mass of small gastroliths and a toothless beak was seen as a specialisation to eat seeds. Ornithuromorphs which still possessed teeth were hypothesised to have been omnivores. The loss of the first toe would be an adaptation to a running lifestyle.

References

{{Taxonbar, from=Q47536173 Early Cretaceous birds of Asia Fossil taxa described in 2018 Prehistoric euornitheans