Parotodus Or Mako: You Make The Call

[siteseer]

I had offered this tooth for sale as a P. benedeni lower anterior but then a member PM'ed me that he thought it looked like a tooth he had considered a Parotodus but was later identified by others as a mako. I've had this tooth for years but I had to respect the comment especially since he's seen a lot of teeth too. I started PM'ing a few other members to get their opinions.

I thought it was a lower anterior because the crown is so straight. It would have a noticeable curve to it if it was from another jaw position. The root seemed thick enough for Parotodus and the tooth seemed to have a substantial enough neck for that as well. I didn't think it could be a hastalis lower anterior because the crown looked too low relative to the size of the root and the root shouldn't be as thick.

The crown is too thick to be a retroflexus and it doesn't have the "elevated platform" Kent pointed out in his 1993 book. The crown is too broad-based to be an oxyrinchus.

One member noted that root symmetry, root and crown width, plus crown length and root length had to be considered. He also said to look at the shape of the crown. Starting from the root, it necks in, then slightly out, and then in to the tip. He said to compare these features in lower anterior makos and Parotodus.

Another member ventured that it had an 80% chance of being a Parotodus and listed his reasons:

1. Vestigial cusplets are less likely to occur on a 2-inch plus mako.

2. I imagine this is a lower right anterior tooth (based on the angles the cusps make with the main crown), and as you said, this is too low of a crown for that type of tooth.

3. The seemingly squared-off distal root lobe seems to be artificial as it resulted from minor damage.

4. Crown widens where you would expect (roughly middle). That doesn't really occur on makos unless it is a retroflexus, which based on the root alone, it clearly is not.

5. Root proportions seem fairly obviously Parotodus (deep, pronounced "U," no real flat facets on the root.

6. The robustness you see in Parotodus becomes much more obvious in teeth well over 2 inches, not so much in smaller teeth.

7. Because this is an anterior tooth and it is very "upright," it eliminates the classic Parotodus "hook" characteristic as a help in identifying the tooth.

Final comment: I think it's much more likely for it to be an "oddball" Parotodus.

Another member allowed that it could a Parotodus but thought it looked a lot more like a lower mako. The blade and root has that look of a mako. It's a nice big tooth but I don't see it as a Parotodus, not after looking at all the ones I have. The root is not as robust as on Parotodus. It looks more like a Cosmopolitodus hastalis A1 or A2. I hope this helps some but remember it could be a Parotodus after all.

I decided to repost photos of the tooth to open up a discussion about it.

Looking at again and comparing it to a Sharktooth Hill Bonebed lower first lateral I have which is fortunately about the same size, I can see that the root isn't as robust. In basal view there doesn't seem to be a lingual protuberance that Parotodus should have on the tooth in question but it still looks quite massive from that angle. The basal root margin is U-shaped though the root lobes seem less symmetrical than they should be for Parotodus. Still, it does appear that the tooth may have suffered some mesial compression when it formed as there is a strange protrusion of root in the "saddle" of the root and a facet that seems to be evidence of something applying pressure to the mesial side.

I've been staring at this tooth too long. Here are three angles:

[Al Dente]

The preservation of this tooth is much more like teeth that come out of the Yorktown than the Pungo River. This would rule out retroflexus. Also retroflexus are a pretty rare find from the mine itself, but fairly common in the reject material which comes from the main ore body deep in the Pungo River Formation, not in the overburden that collectors had access to. The enamel shoulders on this tooth are unlike anything I've seen in a Yorktown Parotodus, also the recurved sides that lead to a wide area in the central blade is unlike anything I've seen in a Yorktown Parotodus. Another feature I see with this tooth that I don't see with Parotodus is the large foramen. Yorktown Parotodus usually have a few tiny pits in the foramen area but the large Yorktown "makos" will have a very prominent foramen like the one on your tooth. I'll post some of my teeth later that show these features. The blade itself looks too long compared with Parotodus teeth which are very short for its size and rapidly come to a point.

Edited February 13, 2014 by Al Dente

[Al Dente]

Here are two Yorktown Parotodus flanked by two lower Yorktown hastalis. The hastalis to the left has a wrinkled dental band similar to your tooth but this is more likely coincidence than a diagnostic feature. The Parotodus at top is fairly straight for Parotodus, probably an anterior tooth. None of these teeth show the expanded central part of the blade that your tooth has. I think that is the only feature that is different than most hastalis that I've seen but as I said in the previous post I have not seen this feature in any Yorktown Parotodus either.

Edited February 13, 2014 by Al Dente

[Al Dente]

Here's a side view of the top Parotodus. It shows how the blades of Yorktown Parotodus tend to lean toward the lingual side and also how short the blade is compared with the root. There is frequently a bulge near the base on the enamel on the labial side that I haven't seen on hastalis teeth.

Edited February 13, 2014 by Al Dente

[Troodon]

I believe its a Mako. The crown just flares out too much. Missed seeing you in Tucson.

[MarcoSr]

I agree pretty closely with Al Dente.

Features of your tooth that I would consider include root symmetry (slight damage to the one root lob does accentuate non symmetry), maximum root width to crown width at the base of the crown but especially crown length to root length. This last feature of your tooth, even if your tooth is a lower A1,which I believe it is, needs to be looked at very closely. Also look at the shape of the crown of your tooth. Starting at the root, it necks in, then slightly out, and then in to the tip. I would compare these features to lower anterior Parotodus and Makos. I considered the root to have damage and not a nutrient pore so I did not consider that feature. Bottom line lack of root symmetry (I understand the damage here), the crown shape and the length of the crown compared to the root length would lead me to a Mako.

Marco Sr.

[cowsharks]

Here's a pic of some Lee Creek Parotodus teeth. These are from Dave Seigert's collection. If I can find my original pic that is larger, I'll post that as well so it's easier to see some of the lowers for comparison.

Daryl.

[cfin1974]

I love the way this tooth is shaped.. If it is a Paratodus i wish they were all shaped like this, it has hips....

[siteseer]

Al Dente,

Thanks for the comments. What you see as a "foramen" is actually just a hole in the root within a continuation of a micro-crack (if that's a technical term). The crown looks long for Parotodus of that size but then it also looks too short for hastalis. The basal root margin should be more clearly a V-shape for hastalis as well. This tooth has a U-shaped basal root margin but it isn't as broadly U-shaped as it would be in a slam-dunk Parotodus.

I agree that it is a Yorktown tooth rather than a Pungo River one.

Do you think this is an example of a mild pathology - the thickness of the root? Distortion of the root during its formation would artificially inflate the size of the neck and could affect the shape of the basal root margin.

Jess

The preservation of this tooth is much more like teeth that come out of the Yorktown than the Pungo River. This would rule out retroflexus. Also retroflexus are a pretty rare find from the mine itself, but fairly common in the reject material which comes from the main ore body deep in the Pungo River Formation, not in the overburden that collectors had access to. The enamel shoulders on this tooth are unlike anything I've seen in a Yorktown Parotodus, also the recurved sides that lead to a wide area in the central blade is unlike anything I've seen in a Yorktown Parotodus. Another feature I see with this tooth that I don't see with Parotodus is the large foramen. Yorktown Parotodus usually have a few tiny pits in the foramen area but the large Yorktown "makos" will have a very prominent foramen like the one on your tooth. I'll post some of my teeth later that show these features. The blade itself looks too long compared with Parotodus teeth which are very short for its size and rapidly come to a point.

[siteseer]

Troodon,

Thanks for the comment. That's another strike against Parotodus.

When you get a chance, please PM me to let me know what I missed. I got a work project at exactly the wrong time so I couldn't go. It bummed me out.

Jess

I believe its a Mako. The crown just flares out too much. Missed seeing you in Tucson.

[siteseer]

Daryl,

Thanks for the photo. Wow, that's quite a collection.

Jess

Here's a pic of some Lee Creek Parotodus teeth. These are from Dave Seigert's collection. If I can find my original pic that is larger, I'll post that as well so it's easier to see some of the lowers for comparison.

Daryl.

[MarcoSr]

Do you think this is an example of a mild pathology - the thickness of the root? Distortion of the root during its formation would artificially inflate the size of the neck and could affect the shape of the basal root margin.

Jess

Jess

I think the root could be pathologic as the result of a feeding injury, like a ray spine into the jaw, When I first saw your tooth, I thought that the root had suffered some kind of impact damage/injury. If your tooth was forming, a ray spine through the jaw could have caused the hole in the root and the small bulge in the root above the hole. The injury could have caused other pathologic features in the root.

Marco Sr.

[siteseer]

Marco Sr.,

Yeah, I'm leaning toward pathology.

The other thing I meant to add is that this tooth is reminiscent of the "bulky isurus" tooth form you see in the STH Bonebed. It's the one that has been interpreted as either a hastalis lower tooth variant, a planus lower, or its own species. In fact, I have one of those teeth which had been ID'ed as a possible Parotodus and it is deformed so I see why the original collector had it as a "maybe." That tooth was easier to identify because it has an incomplete cutting edge on one side which can be an indicator of that tooth form

Jess

Jess

I think the root could be pathologic as the result of a feeding injury, like a ray spine into the jaw, When I first saw your tooth, I thought that the root had suffered some kind of impact damage/injury. If your tooth was forming, a ray spine through the jaw could have caused the hole in the root and the small bulge in the root above the hole. The injury could have caused other pathologic features in the root.

Marco Sr.

[MarcoSr]

Marco Sr.,

Yeah, I'm leaning toward pathology.

The other thing I meant to add is that this tooth is reminiscent of the "bulky isurus" tooth form you see in the STH Bonebed. It's the one that has been interpreted as either a hastalis lower tooth variant, a planus lower, or its own species. In fact, I have one of those teeth which had been ID'ed as a possible Parotodus and it is deformed so I see why the original collector had it as a "maybe." That tooth was easier to identify because it has an incomplete cutting edge on one side which can be an indicator of that tooth form

Jess

Jess

It is interesting that you bring up lower teeth from the STH Bonebed. I also thought of the STH Bonebed when I first saw your tooth. My sons have found several lowers with bulky roots in our trips out to Bakersfield and your tooth reminded me of them.

Marco Sr.