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zygodaktylne tropy z wczesnej kredy
http://forum.dinozaury.com/viewtopic.php?f=17&t=1031
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Autor:  d_m [ 28 marca 2007, o 16:55 ]
Tytuł:  zygodaktylne tropy z wczesnej kredy

Earliest zygodactyl bird feet: evidence from Early Cretaceous roadrunner-like tracks http://www.springerlink.com/content/hl850l4128573g33/?p=3bfb6172d544409a886063ac94ae11f3&pi=0
Cytuj:
Abstract. Fossil footprints are important in understanding Cretaceous avian diversity because they constitute evidence of paleodiversity and paleoecology that is not always apparent from skeletal remains. Early Cretaceous bird tracks have demonstrated the existence of wading birds in East Asia, but some pedal morphotypes, such as zygodactyly, common in modern and earlier Cenozoic birds (Neornithes) were unknown in the Cretaceous. We, herein, discuss the implications of a recently reported, Early Cretaceous (120–110 million years old) trackway of a large, zygodactyl bird from China that predates skeletal evidence of this foot morphology by at least 50 million years and includes the only known fossil zygodactyl footprints. The tracks demonstrate the existence of a Cretaceous bird not currently represented in the body fossil record that occupied a roadrunner (Geococcyx)-like niche, indicating a previously unknown degree of Cretaceous avian morphological and behavioral diversity that presaged later Cenozoic patterns.


We wczesnokredowych osadach Chin znaleziono zygodaktylne (zob. http://en.wikipedia.org/wiki/Image:Bird-feets.png) tropy ptaka, podobne do tych jakie dzi?? zostawia kukawka (zob. http://en.wikipedia.org/wiki/Geococcyx). ZwiÄ?ksza to naszÄ? wiedzÄ? o r????norodno??ci mezozoicznych ptak??w.
Obrazek
kukawka (ang. roadrunner) Stru?? PÄ?dziwiatr :mrgreen:

EDIT 01.04.2007: Komentarz na blogu Pharyngula: http://scienceblogs.com/grrlscientist/2 ... ird_fr.php
Obrazek

Autor:  Dominik [ 28 marca 2007, o 19:31 ]
Tytuł: 

Hehe, to znale??li??my pierwotnego Strusia PÄ?dziwiatra :D Teraz tylko szukaÄ? Kojota!

Autor:  dilong [ 17 kwietnia 2007, o 17:15 ]
Tytuł: 

Hmm...czyli ptaki mezozoiczne, a?? tak siÄ? nie r????ni??y od wspolczesnych pobratymc??w.

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