Bohaiornithidae is a group of early enantiornithean stem-birds from the early Cretaceous Period of China. All undisputed Bohaiornithidae specimens come from the northeast of present-day China – specifically, the eastern and southern foothills of the Greater Khingan mountains –, and date to the early Aptian age, roughly 125–120 million years ago. As of 2024 they are not certainly known from outside this limited region and timeframe, even though there and then they were a prominent – and probably predatory, unlike the bulk of their relatives – element of the local fauna,
Bohaiornithidae is a group of early enantiornithean stem-birds from the early Cretaceous Period of China. All undisputed Bohaiornithidae specimens come from the northeast of present-day China – specifically, the eastern and southern foothills of the Greater Khingan mountains –, and date to the early Aptian age, roughly 125–120 million years ago. As of 2024 they are not certainly known from outside this limited region and timeframe, even though there and then they were a prominent – and probably predatory, unlike the bulk of their relatives – element of the local fauna, namely the Jehol Biota. The taxon Bohaiornithidae was established by Wang and colleagues in 2014. They defined it as the natural group formed by all descendants of the common ancestor of the type species, Bohaiornis guoi, and Shenqiornis mengi.
==Description== Similar to most enantiornitheans, bohaiornithids possessed teeth rather than a beak as in modern birds, although they could be distinguished from other enantiornitheans due to the structure of their teeth. Their teeth were large, robust and somewhat conical, but had sharply pointed tips which curved backwards. The first few teeth of the premaxillae are smaller than the rest of the teeth, but the other teeth in the front of the mouth were larger than those in the back. left|thumb|225x225px|A reconstruction of the skull of Bohaiornis|Bohaiornis guoi Bohaiornithids also had lateral trabeculae (a pair of long and thin bony projections on the rear edge of the sternum) which not only extended backwards, but also outwards. The tips of each branch of the furcula (wishbone) are wide and rounded in bohaiornithids, as opposed to the tapering tips in other enantiornitheans. Their scapulae (shoulder blades) slightly curve downwards, created a convex top edge and concave lower edge. Bohaiornithids also had gradually tapering pygostyles. A bohaiornithid's second (innermost) toes were thicker than their other toes, while their third (middle) toes were long and thin and all of their toe claws were very long and curved.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).