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Re: Richardostesia teeth

Jaime A. Headden wrote-

Michael Mortimer (mickey_mortimer111@msn.com) wrote:

<Because they both have very tiny serrations.  So does Nuthetes, which I
believe falls into the range of Richardoestesia morphotypes.>

It is not so much the size of the serrae as the shape of the serrae, being
low, and nearly quandrangular, along with size distribution along the carinae.
The shapes oft he teeth are also very coincident, with all teeth attributed to
this genus being relatively straight with minimal recurvature. The *R.
isoceles* teeth are just less recurved and in fact less recumbent than the
teeth attributed to *R. gilmorei*.

Denticle shape is not uniform/distinct in the genus, as noted by Sankey et al. (2002) for R. gilmorei- "Denticle tips can be slightly pointed, rounded, or flattened." While she describes R. isosceles as- "Denticle tips are straight or slightly rounded, but not pointed."
Similarly, all teeth referred to Richardoestesia are not relatively straight. Again, describing R. gilmorei- "Isolated teeth vary in curvature from almost completely straight (0.1 mm curvature) to strongly recurved (0.7 mm curvature)."
The denticle size distribution along the carinae for R. gilmorei ("Denticle size varies slightly along the carinae, with smaller ones at the base and tip.") is not distinct from Saurornitholestes ("Denticle size varies along the carina, they tend to be smaller at the base and tip of teeth."). R. isosceles has a different size distribution though- "Posterior denticles are ... uniformly-sized along tooth,"

Indeed, Sankey later states "Richardoestesia isosceles is included in the genus Richardoestesia
because of the presence of small denticles. However, the shape of the denticles in Richardoestesia gilmorei and isosceles is different."

Mickey Mortimer