RE: Specific names

[bh480@scn.org]

To: dinosaur@usc.edu
From: Ben Creisler bh480@scn.org
Subject: Specific names

Jonathan Wagner comments: "It may not be possible in all 
cases to understand the meaning of the name of an animal 
outside one's own field (or even inside one's own field, 
see _Kritosaurus_ as an example). " I'm curious why this 
name is considered incomprehensible. The derivation is 
from Greek kritos "separated," past participle of Greek 
krino "divide, separate, part," originally in the physical 
sense, but later as "selected, chosen, choice." Brown 
almost certainly had the basic physical meaning in mind 
for Kritosaurus "separated lizard." The type material is 
pretty fragmentary and it is certainly NOT "choice"--but 
the short diagnosis states that the "quadrate and jugal 
[were] completely separated by quadrato-jugal," seen as 
a "distinct modification" from the "Trachodon form." The 
supposed separation of the bones does not appear to be 
real; cheek bones in hadrosaurs were somewhat loose to 
allow lateral movement in chewing (pleurokinesis), a 
detail Brown was unaware of.  However, the apparent 
separation of the quadrate and jugal seems a plausible 
explanation for the name when the animal is based almost 
entirely on a partial skull. For more details, see my 
dinosaur etymologies at 
http://www.dinosauria.com/dml/dmlf.htm. Any idea that the 
name is supposed to mean "noble lizard" can be dismissed.
I also looked up the original description of 
Deltatheridium pretrituberculare: Deltatheridium "little 
delta (tooth) beast" refers to the triangular cusps on the 
molars; pretrituberculare is a neuter-gender Latin-version 
of the term "pretritubercular," once used to describe a 
type of molar tooth not quite at the evolutionary stage of 
the "tritubercular" form found in later mammals. I'm not 
certain this terminology is used anymore among Mesozoic 
mammal scholars.