[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Geographic Distribution of Deinonychosauria
>> True, but the stages don't last so long that one cannot infer
>> distributions of nonvolant taxa fairly well from knowledge of the
>> topographical layout (particularly if taking into account
> Maastrichtian: 5 Ma, Campanian: 13 Ma...
> Many stages in the Jurassic are estimated to be about 4 Ma long, which
> is also the confidence interval on their start and end dates.
Myr, not Ma. Ma is for dates, not durations.
>> Apart from that, one can assume that open seas/oceans are a barrier
>> to dispersal until proven otherwise, and simply deal with the major
>> land areas (i.e. as isolated by open sea and high mountains).
> That's where uncertainties in paleogeographic reconstructions come in.
> How much connection was there between South America and Antarctica and
> between Antarctica and India in the Cretaceous? For how long? What about
> Antarctica and Australia or Madagascar and India? Or India and Africa?
> Etc., blah, blah.
Or the patchwork quilt of terranes that is the Asian-North American