Fred Ruhe
Well-known member
120 million year old fossil bird found in Japan, CT-scanned and recreated with 3D printer, will go on display in July at Fukui Prefectural Dinosaur Museum; the bones are uncrushed; this appears to be a new, undescribed taxon, similar to Confuciusornis and about the size of a pigeon (in Japanese).
(click photo to expand)
http://news.livedoor.com/article/detail/14687753/
http://www.chunichi.co.jp/article/fukui/20180509/CK2018050902000027.html
NOTE: This must be the fossil bird mentioned in this SVP (Society of Vertebrate Paleontology) abstract from 2016, meaning it presumably will be described officially soon:
Yakuya Imai, Yoichi Azuma, Masateru Shibata & Kazunori Miyata, 2016
REPORT ON A FOSSIL BIRD FROM THE LOWER CRETACEOUS KITADANI FORMATION, TETORI GROUP, FUKUI, JAPAN
Our understanding about the evolution of the Early Cretaceous birds has
dramatically improved due to recent numerous discoveries of the well-preserved fossil birds from the northeastern and northwestern China. However, the Early Cretaceous fossil birds are poorly known from other regions of Asia, making the fossil record heavily biased. Here, we report the first three-dimensionally preserved, nearly complete fossil bird from Japan, outside of the Lower Cretaceous of China in Asia. The specimen comes from the Kitadani Formation, the Tetori Group, Fukui, Japan. The Kitadani Formation is composed of the late Barremian to the early Aptian fluvial deposits, and has yielded diverse vertebrate remains including non-avian dinosaurs. The specimen was collected from the pale-green siltstone which likely represents a floodplain deposit. The skeleton is disarticulated and preserves most of the parts of the body three-dimensionally; such state of preservation is uncommon for the Early Cretaceous bird fossils. The skull is present but severely fragmented. The pygostyle is slender and has a rectangular shape. The coracoid has semi-circular articulation surface. The furcula is robust and boomerangshaped. Its round, inflated area at the both ends of the clavicular rami and lack of the hypocleidium resemble the furcula of Confuciusornis sanctus. The humerus measures 8.8 cm long and is similar to that of Jeholornis prima in having a convex humeral head and a prominent deltopectral crest, whose length approaches about 40% of the length of the humerus. The humerus bears a unique depression at the proximal end of the deltopectral crest. Ulna/femur length ratio is 1.33, indicating the specimen has relatively long forelimbs, but not to the degree seen in other Early Cretaceous basal birds such as J. prima (1.45) and Sapeornis chaoyangensis (1.66). The metacarpal III is long and slender. The femur, which measures 6.1 cm long, is slender compared to other basal Early Cretaceous birds. Such osteological characters as simple and robust furcula, and long and slender metacarpal III may indicate that the specimen is more basal than Ornithothoraces within Avialae. While the specimen shares some features with C. sanctus and J. prima, it exhibits a combination of characters that is not seen in other Early Cretaceous basal birds. The specimen probably represents the early stage of the evolution toward powered flight. A study utilizing the micro-computed-tomography on the specimen is undertaken to better understand its morphology and taxonomic position.
Enjoy,
Fred
(click photo to expand)
http://news.livedoor.com/article/detail/14687753/
http://www.chunichi.co.jp/article/fukui/20180509/CK2018050902000027.html
NOTE: This must be the fossil bird mentioned in this SVP (Society of Vertebrate Paleontology) abstract from 2016, meaning it presumably will be described officially soon:
Yakuya Imai, Yoichi Azuma, Masateru Shibata & Kazunori Miyata, 2016
REPORT ON A FOSSIL BIRD FROM THE LOWER CRETACEOUS KITADANI FORMATION, TETORI GROUP, FUKUI, JAPAN
Our understanding about the evolution of the Early Cretaceous birds has
dramatically improved due to recent numerous discoveries of the well-preserved fossil birds from the northeastern and northwestern China. However, the Early Cretaceous fossil birds are poorly known from other regions of Asia, making the fossil record heavily biased. Here, we report the first three-dimensionally preserved, nearly complete fossil bird from Japan, outside of the Lower Cretaceous of China in Asia. The specimen comes from the Kitadani Formation, the Tetori Group, Fukui, Japan. The Kitadani Formation is composed of the late Barremian to the early Aptian fluvial deposits, and has yielded diverse vertebrate remains including non-avian dinosaurs. The specimen was collected from the pale-green siltstone which likely represents a floodplain deposit. The skeleton is disarticulated and preserves most of the parts of the body three-dimensionally; such state of preservation is uncommon for the Early Cretaceous bird fossils. The skull is present but severely fragmented. The pygostyle is slender and has a rectangular shape. The coracoid has semi-circular articulation surface. The furcula is robust and boomerangshaped. Its round, inflated area at the both ends of the clavicular rami and lack of the hypocleidium resemble the furcula of Confuciusornis sanctus. The humerus measures 8.8 cm long and is similar to that of Jeholornis prima in having a convex humeral head and a prominent deltopectral crest, whose length approaches about 40% of the length of the humerus. The humerus bears a unique depression at the proximal end of the deltopectral crest. Ulna/femur length ratio is 1.33, indicating the specimen has relatively long forelimbs, but not to the degree seen in other Early Cretaceous basal birds such as J. prima (1.45) and Sapeornis chaoyangensis (1.66). The metacarpal III is long and slender. The femur, which measures 6.1 cm long, is slender compared to other basal Early Cretaceous birds. Such osteological characters as simple and robust furcula, and long and slender metacarpal III may indicate that the specimen is more basal than Ornithothoraces within Avialae. While the specimen shares some features with C. sanctus and J. prima, it exhibits a combination of characters that is not seen in other Early Cretaceous basal birds. The specimen probably represents the early stage of the evolution toward powered flight. A study utilizing the micro-computed-tomography on the specimen is undertaken to better understand its morphology and taxonomic position.
Enjoy,
Fred
