''Eogranivora'' is a

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

genus, belonging to the Ornithuromorpha, that lived in the area of present-day

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

during the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

. Its

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

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 preserve ...

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

. The generic name combines a Greek ''eos'', "dawn", with

Neo-Latin Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...

''granivora'', "group of seed eaters", in reference to the species being the oldest known seed-eating ornithuromorph bird. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

means "toothless" in

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

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

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

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

Yixian Formation The Yixian Formation (; formerly Romanization of Chinese, transcribed as Yihsien Formation or Yixiang Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the Barremian stage of the Early Cretaceous. I ...

dating from the early

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

, at about 125 million years old. It consists of a nearly complete skeleton with a 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. In other words, a crop is a plant or plant product that is grown for a specific purpose such as food, Fiber, fibre, or fuel. When plants of the same spe ...

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 ...

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 pubis or pubic bone () forms the lower and anterior part of each side of the hip bone. The pubis is the most forward-facing (ventral and anterior) of the three bones that make up the hip bone. The left and right pubic bones ar ...

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 (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...

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 tree ...

, below the

Hongshanornithidae Hongshanornithidae is an extinct group of early Ornithuromorpha, ornithuromorph birds from the early Cretaceous period of China. It includes the genus, genera ''Hongshanornis'' (the type genus) and ''Tianyuornis'' from the Yixian Formation of In ...

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

omnivore An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

s. The loss of the first toe would be an adaptation to a running lifestyle.

References

{{Taxonbar, from=Q47536173 Euornithes Early Cretaceous dinosaurs of Asia Fossil taxa described in 2018