Re: [dinosaur] What is the earliest known bird

[David Marjanovic <david.marjanovic@gmx.at>]

> How are you doing in these crazy times?

I'm at least as productive as before, actually. I was already socially isolated 
(half of the building is a construction site, so it isn't possible to put most 
people in logical places in the building), so nothing changed there, and I 
don't often need the workplace computer or the dead-trees library.

> If you buy some of the molecular clock estimates that have been published

But that's it: molecular clocks have to be calibrated by the fossil record. If 
the calibrations are wrong, the results will be wrong. If there aren't enough 
calibrations, the results will also be wrong. If the calibrations are too 
one-sided (e.g. not enough maximum ages to go with the minimum ages), the 
results will be wrong, too.

> That said, I think two pre-Campanian records than deserve more analysis are 
> Turonian Tingmiatornis and Agnolin et al.'s Turonian-Coniacian galliform-like 
> coracoid.

Ooh, thanks. I didn't even know about the latter and sort of forgot about the 
former, so I don't mention them in the paper. That said, ornithologists have a 
long history of reading too much into isolated coracoids; the holotype of 
*Tingmiatornis* is an isolated humerus, the referred material is another 
humerus and an ulna, and the description doesn't even bother with a 
phylogenetic analysis because there aren't enough characters there â 
*Tingmiatornis* could easily be a hesperornithean-grade animal.

(By the way: avis is a she, but ornis is a he, so it's *Tingmiatornis 
arctic_us_*.)