New Early Cretaceous bird tracks from Korea

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com

A new paper in Ichnos:


Jeong Yul Kim, Min Kyeong Kim, Mun Seop Oh & Chang Zin Lee (2013)
A New Semi-Palmate Bird Track, Gyeongsangornipes lockleyi ichnogen. et
ichnosp. nov., and Koreanaornis from the Early Cretaceous Jindong
Formation of Goseong County, Southern Coast of Korea.
Ichnos 20 (2): 72-80
DOI:10.1080/10420940.2013.787071
http://www.tandfonline.com/doi/full/10.1080/10420940.2013.787071#.UaJ8qEC1FcQ

Well-preserved semi-palmate bird tracks and small wading bird tracks
from the Early Cretaceous Jindong Formation of Deokmyeongri,
Hai-myeon, and Naesanri, Donghae-myeon, Goseong County, South
Gyeongsang Province, southern coast of Korea, are herein described as
Gyeongsangornipes lockleyi ichnogen. et ichnosp. nov. and Koreanaornis
hamanensis, respectively. Gyeongsangornipes lockleyi is a small
asymmetrical, strong mesaxonic bird track, about 31–32 mm long and
40–41 mm wide, without a clear hallux impression. Divarication between
digits II and III is much larger than that between digits III and IV.
Webbing is clearly preserved, and the web between digits II and III is
smaller than that between digits III and IV, which shows strong
asymmetry of web development. Two different-sized Gyeongsangornipes
lockleyi appear to suggest two different-size classes of web-footed
birds. Koreanaornis hamanensis is a small sub-symmetrical wading bird
track, about 26–28 mm long and 29–39 mm wide, without clear hallux
impressions. The divarication between digits II and III (59°–66°)°) is
larger than that between digits III and IV (44°– 58°). Divarication
between digits II and IV is 103°–123°. Length of digit III (26–28 mm)
is longer than those of digits II and III (about 18 mm). These new
records shed light on patterns of bird track diversity and abundance
in the Cretaceous of Korea and document a diverse avian fauna that
flourished during the Cretaceous.