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Re: [dinosaur] How many end-Cretaceous dinosaur genera were there

I am not aware of any current world-wide census of terminal late Cretaceous 
Dinosaur genus/species. But there is an estimate of between 628 and 1076 
dinosaur species existed prior to the K-Pg event. I'm referencing the study by 
Jean Le Loeuff (2012).


Loeuff Le J (2012). "Paleobiogeography and biodiversity of Late Maastrichtian 
dinosaurs: how many dinosaur species became extinct at the Cretaceous-Tertiary 
boundary?". Bulletin de la Société Géologique de France. 183 (6): 547–559. 


The global Late Maastrichtian non-avian dinosaur apparent biodiversity is 
extensively surveyed for the first time. It amounts to 104 species (including 
unnamed forms) in 2010. The real biodiversity being obscured by taphonomical 
biases and the scarcity of the continental fossil record, a species-area 
relationship is used to estimate it. The results show that several hundreds 
(between 628 and 1078) non-avian dinosaur species were alive in the Late 
Maastrichtian, which is almost an order of magnitude above previous estimates. 
Because of the complex Late Cretaceous palaeobiogeography, discussions about 
dinosaur extinction should be based on this estimated real global biodiversity, 
not on the apparent biodiversity of a single area. Given the mean duration of 
dinosaur genera (7.7 Ma), the presence of so many dinosaur species in the 
Latest Cretaceous is consistent with the termination of most lineages at the 
Cretaceous-Tertiary boundary (the Late Maastrichtian sub-stage is 2.8 m.y. 
long). The Late Maastrichtian dinosaurian biodiversity is therefore consistent 
with the sudden extinction of the group following the Chicxulub impact.

---- Poekilopleuron <dinosaurtom2015@seznam.cz> wrote: 
> Good day to all list members,

I would like to ask, exactly how many dinosaur genera/species are known to 
be still present globally at the end of the Maastrichtian, 66 mya? Thank you
very much