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New Chinese Jehol bird Longirostravis hani



dinosaur@usc.edu
From: Ben Creisler bh480@scn.org
New Jehol Bird
In case this item has not been mentioned here, the online advance articles
for Naturwissenschaften this week include the following:

Hou L., Chiappe, L. M.,  Zhang F., Chuong C.M., New Early Cretaceous fossil
from China documents a novel trophic specialization for Mesozoic birds.
Naturwissenschaftern online Dec. 17, 2003. 

Abstract We report on a new Mesozoic bird, Longirostravis hani, from the
Early Cretaceous Jehol Biota of northeastern China. The new taxon has a
long, slender rostrum and mandible, and a small number of rostralmost
teeth. Postcranial characters such as a furcular ramus wider ventrally than
dorsally, a centrally concave proximal margin of the humeral head, and a
minor metacarpal that projects distally more than the major metacarpal,
support the placement of Longirostravis within euenantiornithine
Enantiornithes, the most diverse clade of Mesozoic birds. The morphology of
the skull, however, suggests that Longirostravis had a probing feeding
behavior, a specialization previously unknown for Enantiornithes. Indeed,
this discovery provides the first evidence in support of the existence of
such a foraging behavior among basal lineages of Mesozoic birds.
Text Highlights:
Enantiornithes Walker 1981 
Euenantiornithes Chiappe 2002 
Longirostravis gen. nov. 
Longirostravis hani sp. nov. 

 Latin...meaning a bird with a long rostrum; hani is in honor of its
discoverer, Mr. Han.
Holotype 
IVPP V 11309 (Institute of Vertebrate Paleontology and Paleoanthropology,
Chinese Academy of Sciences), a quail-sized, nearly complete and
articulated skeleton surrounded by much of its plumage 
Locality and horizon 
Yixian County, Liaoning Province, northeastern China. Middle to upper
Yixian Formation, Early Cretaceous 
Diagnosis 
Small euenantiornithine bird with the following autapomorphies: long,
tapering, and slightly curved rostrum and mandible; dentition restricted to
cranial tip of rostrum and mandible; lateral process of sternum with
three-branched, moose-horn-like distal expansion.
...skull....has a long (35 mm) and tapering rostrum and mandible that
gently curve downwards ...Dentition is restricted to the tip of the skull,
... ten small (~0.5 mm) and conical (~15o) teeth ...arranged in pairs in
the combined premaxillae and rostralmost portion of the dentaries
Estimated skull length 36.0
....
A number of derived characters support the inclusion of Longirostravis hani
within the euenantiornithine Enantiornithes...presence of a convex lateral
margin of the coracoid (although in Longirostravis the condition is not as
marked as in other euenantiornithines), a ventral margin of the furcula
that is wider than its dorsal margin, a proximal margin of the humeral head
that is concave in its central position, a minor metacarpal that projects
distally more than the distal end of the major metacarpal, and a very
narrow and deep intercondylar sulcus of the tibiotarsus. Other derived
characters shared ...include the presence of a cranial fork on the
pygostyle, a scapula with an acromion that is transversally wider than
deep, a distinct distal expansion of the lateral process of the sternum,
and a subcircular-shaped metacarpal I....
We suggest that the long and slender bill of Longirostravis was probably
best for probing in the mud. The length of the bill of Longirostravis falls
within the range of those of extant charadriiforms, such as oystercatchers
(Haematopodidae) and redshanks (Scolopacidae), whose diets are primarily
based on worms, bivalves, and crustaceans... 

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