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

K/T extinction (forams and birds)

Forams were not wiped out. Class Foraminiferea actually came through K/T almost unscathed in terms of ordinal diversity. Order Involuntinida (which made it through the Permian extinction) apparently did not make it through K/T (but who knows, it may be found in the early Paleozoic someday).
But most Cretaceous foram orders made it through and are still with us today: Monothalamida, Allogromiida, Astrorhizida, Haplophragmiida, Spirillinida, Miliolida, Lagenida, Robertinida, Globigerinida, Buliminida, Cassidulinida, Nonionida, Plaorbulinia, Asterigerinida, Discorbida, and Rotaliida. Sadly, Order Orbitoidida made it through K/T, but only made it to the Eocene.
As for Aves, the neornitheans probably just made it through by the "skin of their beaks" (attempted humour). Cladistically it appears there were a minimum of four surviving clades (i.e., a minimum of four bird species):
(1) a paleognath (tinamou-like); (2) a galliform; (3) an anseriform; and (4) at least one "shore-bird" (a charadriiform and/or a procellariiform). Not surprisingly, the bird survivors were apparently in the Southern Hemisphere. All things considered, I'd say forams came through the disaster fairly well (disaster doesn't seem like strong enough word for K/T--- a ghastly time to have been alive, especially on land).
Get your FREE download of MSN Explorer at http://explorer.msn.com