Tag Archives: Birds

News flash: Bird fingers

"Embryological Evidence Identifies Wing Digits in Birds as Digits 1, 2, 
and 3"

Koji Tamura, Naoki Nomura, Ryohei Seki, Sayuri Yonei-Tamura, and Hitoshi
Yokoyama

Science 11 February 2011:
Vol. 331 no. 6018 pp. 753-757
DOI: 10.1126/science.1198229

Abstract:

The identities of the digits of the avian forelimb are disputed. Whereas
paleontological findings support the position that the digits correspond 
to digits one, two, and three, embryological evidence points to digit 
two, three, and four identities. By using transplantation and 
cell-labeling experiments, we found that the posteriormost digit in the 
wing does not correspond to digit four in the hindlimb; its progenitor 
segregates early from the zone of polarizing activity, placing it in the
domain of digit three specification. We suggest that an avian-specific 
shift uncouples the digit anlagen from the molecular mechanisms that 
pattern them, resulting in the imposition of digit one, two, and three 
identities on the second, third, and fourth anlagens.

Cheers!!

--Mikko

Giant fossil bird found on ‘hobbit’ island of Flores

Fossils of the genus Leptoptilos from the Pleistocene of Liang Bua, Flores, Indonesia, belong to a new species of giant marabou stork, Leptoptilos robustus sp. nov. This giant bird, estimated at 1.80 m in length, was similar in dimensions to extant Leptoptilos dubius, except for the tibiotarsus.  An evolutionary lineage is proposed in which a volant L. dubius-like ancestor in the Middle Pleistocene evolved into the Late Pleistocene L. robustus on Flores, with a concomitant reduction of the ability to fly and an increase in body size. The large body size and terrestrial lifestyle of L. robustus are responses to an unbalanced, insular environment with abundant prey items and a lack of mammalian carnivores, and emphasize the extraordinary nature of the Homo floresiensis fauna.

In the news:

http://news.bbc.co.uk/earth/hi/earth_news/newsid_9261000/9261713.stm

The paper:

http://onlinelibrary.wiley.com/doi/10.1111/j.1096-3642.2010.00616.x/full