[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Enantiornithines



Jean-Michel (Aegyptiacus@aol.com) wrote:

<I've been quite a while on this but I've always wondered about 
enantiornithes. What characteristics make them "opposite" birds and not 
"true" birds? Were they volant?>

  Enantiornithes includes such birds as *Sinornis* and *Enantiornis*
itself, and many birds in the groups have remarkably long forelimbs and
full feather compliments, so they could fly. The thing that makes enants
(for short) "opposite" other birds is the configuration of the triosseal
canal between scapula and coracoid: in normal birds and *Confuciusornis*,
the lateral border of the canal is formed by the acrocoracoid process of
the coracoid, which projects dorsally and is very distinct, and sits
lateral to the acromion process of the scapula; however, enants have the
reverse: the acromion of the scapula is lateral to the acrocoracoid, and
furthermore, the acrocoracoid process is shorter. Since the acromion is
where the furcula articulates, this also effects the entire shoulder
configuration, but not in any way it would appear to affect its flight
ability, and does not affect the relationship of the humerus or the
glenoid orientation.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com