Siberian chiffchaff Siberian chiffchaff Siberian chiffchaff ("Phylloscopus (collybita) tristis") is a leaf-warbler which is usually considered a subspecies of the common chiffchaff, but may be a species in its own right. Siberian chiffchaff breeds in Siberia east of the Pechora River and winters in the lower Himalayas. It is also regularly recorded in western Europe in winter, and it is likely that the numbers involved have been underestimated due to uncertainties over identification criteria, lack of good data and recording policies (Sweden and Finland only accept trapped birds). Because of their unfamiliar appearance, British records in the 1950s and 1960s were originally
The Origin of Birds in fact, was decidedly reptilian and generally opposed to that of modern birds. This included the pelvis, which lacks a pectineal process and has a very different os sacrum from modern birds, as well as the carpus, which Heilmann wrote exhibited the same phenomena found in the wrists of modern reptiles. Its tail was also noted by Heilmann as being extremely reptilian and resembling nothing known of modern birds. He goes on to state that other features of "Archaeopteryx", however, are remarkably birdlike and bear little resemblance to their reptilian analogues. The hand of "Archaeopteryx" is observed as being one