Echinoid Goniophorus scotti vs. G. whitneyi (Texas Cretaceous)

[JamieLynn]

I have a question about the echinoid Goniophorus - Texas Cretaceous. 

 

I have found what I have always seen ID'd as G. scotti in the Del Rio/Grayson formation

I recently found  two in what I am fairly sure is Duck Creek Formation. 

 

In the HGMS book on Echinoids, it has two Goniophorus listed - scotti and whitneyi. 

It says there is a difference in size and "markedly different" apical ornamentation, which I am definitely seeing on these. 

But it also says it is considered by some paleontologists as the same, not two different ones. 

 

In the book, according to Ikens - G. whitneyi is found in Del Rio/Grayson and is larger with different decor wheras

G scotti is found in Duck Creek formation and is smaller and more geometric apical (star shaped) which I definitely see in these specimens.

 

So my question is - is the distinction between the two species valid? 

This one is from the Del Rio Form. which HGMS says is G. whitneyi

 

These two are from Duck Creek which HGMS say is G. scotti