Dakotaraptor steini ?

[Joebiwan3]

This next tooth was listed as a possible dakotaraptor steini...what do you guys think? Sorry for the finger placement in some of the pictures.....from the hell creek formation in powder river co. , MT. The size is 15/16 " and Serrations on the posterior of the tooth are 5 per mm and 10 per 2 mm. The anterior serrations look smaller and look to be about 6 per mm....

@Troodon

[Joebiwan3]

[Joebiwan3]

[Joebiwan3]

[Joebiwan3]

[Joebiwan3]

[Joebiwan3]

[Troodon]

Need an accurate anterior density count not about 6

 

Just need a couple of more dimensions at the base

CBW and CBL

CH is 24 please verify

[Joebiwan3]

If im couting the serrations on the mm lines on the ruler its anterior 6 posterior 5 per mm...if counting in between the mm lines im seeing 4 anterior and 5 posterior under magnifying glass .......

[Joebiwan3]

[Joebiwan3]

[Joebiwan3]

Cbl 9 mm cbw 4mm

[MarcoSr]

@Troodon  Are the below measurements a universal way to help ID all theropod teeth or are they used for only certain families/genera/species?  I'm assuming that ratios of the below measurements are used to help with the ID.  Can you list the diagnostic ratios of the below measurements i.e. which ratios are you using to ID this tooth?

 

 

 

Marco Sr.

[Troodon]

30 minutes ago, MarcoSr said:

@Troodon  Are the below measurements a universal way to help ID all theropod teeth or are they used for only certain families/genera/species?  I'm assuming that ratios of the below dimensions are used to help with the ID.  Can you list the diagnostic ratios of the below measurements i.e. which ratios are you using to ID this tooth?

 

Marco Sr.

Multivariate analysis is a tool that helps to diagnose isolated Theropod teeth.  Its by no means a slam dunk or diagnostic because of the similarity of teeth in different species and the variation of teeth in a jaw.   We also have very little published in what dentitions look like so its difficult to compare against.  Not like shark teeth.   With Dakotaraptor we have a paper that shows several characteristics and the ranges of ratios on the holotype that we can compare against.  The ratios we are looking for here are CBR..crown base ratio (CBW/CBL),  CHR...crown height ratio (CH/CBL) and DSID...Denticle size density index.  That why I always say one cannot look at photos to properly ID small teeth

[Joebiwan3]

@Troodon CH is 24 yes 

[Troodon]

2 hours ago, Joebiwan3 said:

im couting the serrations on the mm lines on the ruler its anterior 6 posterior 5 per mm...if counting in between the mm lines im seeing 4 anterior and 5 posterior under magnifying glass .......

 

Big difference on the anterior ones and critical 

[Joebiwan3]

So i guess my question is then are we counting the serrations in between mm lines or is it from mm line to mm line?

[MarcoSr]

1 hour ago, Troodon said:

Multivariate analysis is a tool that helps to diagnose isolated Theropod teeth.  Its by no means a slam dunk or diagnostic because of the similarity of teeth in different species and the variation of teeth in a jaw.   We also have very little published in what dentitions look like so its difficult to compare against.  Not like shark teeth.   With Dakotaraptor we have a paper that shows several characteristics and the ranges of ratios on the holotype that we can compare against.  The ratios we are looking for here are CBR..crown base ratio (CBW/CBL),  CHR...crown height ratio (CH/CBL) and DSID...Denticle size density index.  That why I always say one cannot look at photos to properly ID small teeth

 

Frank

 

Thank you for the information in your reply.  Several shark tooth researchers have published papers that depicted different shark tooth measurement ratios to try to id isolated shark teeth to a genus/species.  However because of the variation of shark tooth features in an individual jaw and within a species and the overlap of tooth features among other different species these measurements/ratios only have very limited usefulness and haven't gained universal acceptance among shark researchers.  However, published extant shark jaws/dentitions and published fossil shark natural, associated, and artifical dentitions really do help tremendously with isolated shark tooth identification. 

 

Marco Sr.

[Troodon]

2 hours ago, Joebiwan3 said:

So i guess my question is then are we counting the serrations in between mm lines or is it from mm line to mm line?

Its full mm so its wherever part of the line you start on the first one you end it on the last one. why doing 5 mm wide accounts for a little variation

[Joebiwan3]

@Troodon ok its looking like anterior 6 and posterior 5 per mm

[Troodon]

Thanks let me take a look and will get back with you.  On this one its a tight call and I'm reaching out to someone that can help with the ID.

[Joebiwan3]

@Troodon thanks....im going to go double check the serration count again. Is there a specific way you do it or is magnifying glass and ruler still my best bet?

[Joebiwan3]

Let me double check the density again on both sides....when i look at other pictures i have on my phone next to the ruler it looks like i have 8 or 9 serrations per 2 mm on the anterior......let me really try and get a definitive count...sorry for the confusion everyone i just wanna make sure i give you the correct info

[Troodon]

Ditto...unfortunately I use a microscope and it's easy.   Use whatever you believe is most accurate but magnification usually gives you better detail.  Not easy when you are dealing with millimeters.  Anyone you know have a scope?

[Joebiwan3]

@Troodon yes thanks for the help on this ....hopefully we can come to a satisfactory answer....once i get in im going to re-measure and re-count.