Jinguofortisidae is an extinct family of early

pygostylia Pygostylia is a group of avialans which includes the Confuciusornithidae and all of the more advanced species, the Ornithothoraces. Definition The group Pygostylia was intended to encompass all avialans with a short, stubby tail, as opposed to ...

avialan Avialae ("bird wings") is a clade containing the only living dinosaurs, the birds. It is usually defined as all theropod dinosaurs more closely related to birds (Aves) than to deinonychosaurs, though alternative definitions are occasionally used ...

s known from the Early Cretaceous, found in northern China.

Description

The Jinguofortisidae are distinguished from other non- ornithothoracine avialans by the following features: the

scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eith ...

and

coracoid A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is prese ...

fused into a

scapulocoracoid The scapulocoracoid is the unit of the pectoral girdle that contains the coracoid and scapula. The coracoid itself is a beak-shaped bone that is commonly found in most vertebrates with a few exceptions. The scapula is commonly known as the ''shoulde ...

; a boomeranged-shaped

furcula The (Latin for "little fork") or wishbone is a forked bone found in most birds and some species of non-avian dinosaurs, and is formed by the fusion of the two pink clavicles. In birds, its primary function is in the strengthening of the thoracic ...

without a hypocleidium; proximal margin of humerus concave centrally;

deltopectoral crest Deltopectoral may refer to; * Clavipectoral triangle, also known as the deltopectoral triangle * Deltopectoral groove * Deltopectoral lymph nodes One or two deltopectoral lymph nodes (or infraclavicular nodes) are found beside the cephalic vein, b ...

large and not perforated; minor metacarpal markedly bowed caudally;

alular The alula , or bastard wing, (plural ''alulae'') is a small projection on the anterior edge of the wing of modern birds and a few non-avian dinosaurs. The word is Latin and means "winglet"; it is the diminutive of ''ala'', meaning "wing". The al ...

digit terminating at the level of the distal end of major metacarpal; and proximal phalanx of the major digit longer than the intermediate phalanx.

Phylogeny

Wang et al. (2018) erected Jinguofortisidae after finding '' Chongmingia'' (previously considered Avebrevicauda ''incertae sedis'' by Wang et al. 2016) to be sister to their new taxon ''Jinguofortis''. In 2023, a third jinguofortisid was described by Li ''et al''. They recovered their new taxon, '' Cratonavis'', as the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to ''Chongmingia''. The results of their

phylogenetic analyses In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

are shown in the

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

below:

References

{{Taxonbar, from=Q60790769 Prehistoric avialans Prehistoric dinosaur families Early Cretaceous birds of Asia Valanginian first appearances Early Cretaceous extinctions