Hadrosaur Or Not

[bone2stone]

I recently found a vertebrae that I think is a Hadrosaur. After taking a look at some others, I'm having second thoughts. It may be tail, I really do not know for sure.

I was told by someone that it was a plesiosaur, but I know that the plesiosaur did not exist during the age when the woodbine of the Dallas/Ft Worth area was an active terrestrial and aquatic environment.

Over the years I have found several of these and these are the last two found.

I have found croc/turtle/shark/fish/and dino material in the woodbine, along with other aquatic fauna such as the ammonites.

I was just curious as to whether I have these identified as tail and or vertebrae.

Just let me know whatcha think, I will take any and all input seriously.

Jess B.

[Regg Cato]

Off the top of my head I see more marine reptile than hadrosaur.

Edited September 16, 2013 by Regg Cato

[bone2stone]

What marine "Reptiles" were in this area at that time. This deposit predates the upper Cretaceous.

I am aware that these look similar to the plesiosaur but did they exist at this time period?

I know it's not crock or turtle and I find teeth as well as gizzard stones and fossil wood quite often.

So my question still remains juvenile hadrosaur (Vert/Tail bones)?

Jess B.

[Auspex]

I may be missing a point, but plesiosaurs span from the earliest Jurassic to the end K, yes?

[rejd]

I may be missing a point, but plesiosaurs span from the earliest Jurassic to the end K, yes?

Yes you are correct Auspex. Here is a quick exert from Wikipedia

Plesiosaurs first appeared in the Early Jurassic (and possibly Rhaetian, latest Triassic) Period^[1] and became especially common during the Jurassic Period, thriving until the Cretaceous–Paleogene extinction at the end of the Cretaceous Period. They had a worldwide distribution.

[Regg Cato]

So after doing a bit of research, I'm pretty confident these are not dinosaurian, and plesiosaur (of some sort) seems the most likely identification.

You'll find several vertebrae that resemble the ones you posted here: http://www.oceansofkansas.com/ks-plesio.html

The length-height ratios for the first specimen doesn't really indicate that it's Hadrosaurid to me, while the centrum of the second one more closely resembles plesiosaur vertebrae (generally the centrum is not as medially constricted in Hadrosaurs).

These observations are based on comparisons with other Hadrosaurid and Plesiosaur vertebrae, in addition to a hadrosaurid vertebra on my desk.

I may be missing a point, but plesiosaurs span from the earliest Jurassic to the end K, yes?

The family existed for about 130 million years; Elasmosaurus, Styxosaurus, and Trinacromersum all lived in LK North America, to give a few examples.

[Ridgehiker]

In general with good specimens from particular caudal vertebra positions one can say a particular specimen is definitely a hadrosaur, ceratopsian, ornithomimid, Tyrannosaurid .....but otherwise most isolated verts can be a few families.

If I was walking in our badlands and looked down and saw your first specimen, I'd assume it was most likely hadrosaur but possibly ceratopsian. The second one, in contrast, is 'not' hadrosaur or ceratopsian. I don't know what it is.

Edmontosarus caudal verts are distinct as hadrosaurs.....Triceratops caudal verts distinct as ceratopsians. However, most of the other genera are some sort of 'in between'. There are so many genera and vertebrae positions that it can identification is tricky without the presence of a type species to compare to.

A note...easier to identify the first one with photo looking down at the top side where the process, etc was attached.

Edited September 16, 2013 by Ridgehiker

[grampa dino]

I first thought was ceratopsian, just from the all a round shape of it.

[Regg Cato]

Do you have any stratigraphic context for these specimens?

[Ridgehiker]

I say hadrosaur, possibly ceratopsian. Grandpa Dino says ceratopsian. He's collected 10 billion vertebrae so I defer to him.

The score is ceratopsian 1.5 to 1.0 over hadrosaur.

[Regg Cato]

Has anyone even compared these with Plesiosaur vertebrae though? The pictures are of two different vertebrae, one of which is definitely not Hadrosaurid.

Compare with http://www.oceansofkansas.com/KS-Plesiosaurs/UNSM1195/FHSM%20VP-16869/FHSM%20VP-16869%20Vert1.jpg

and

Cimoliasaurus magnus

My main issue with it being a Hadrosaur is it appears to be shorter anteroposteriorly than most Hadrosaurid vertebrae, even distal caudals. Ceratopsian is a possible identification, but I would hesitate to think that just yet without any stratigraphic context.

I'm not plesiosaur expert, but the second picture looks rather like a plesiosaur epipodial

Edited September 16, 2013 by Regg Cato

[JohnJ]

I recently found a vertebrae that I think is a Hadrosaur. After taking a look at some others, I'm having second thoughts. It may be tail, I really do not know for sure.

I was told by someone that it was a plesiosaur, but I know that the plesiosaur did not exist during the age when the woodbine of the Dallas/Ft Worth area was an active terrestrial and aquatic environment.

Over the years I have found several of these and these are the last two found.

I have found croc/turtle/shark/fish/and dino material in the woodbine, along with other aquatic fauna such as the ammonites.

I was just curious as to whether I have these identified as tail and or vertebrae.

Just let me know whatcha think, I will take any and all input seriously.

Jess B.

The formation Jess refers to is the Woodbine Formation - which is an Upper Cretaceous (late Cenomanian) strata.

[bone2stone]

Do you have any stratigraphic context for these specimens?

These both came from the woodbine south of the DFW airport.

First one was washed out completely and the darker one was taken directly from the matrix

the dark shale layer below the Calycoceras zone.

Jess B

[vertman]

OK, I guess I will weigh in with my .02 for whatever it is worth. I have collected the dark shale layer in the Woodbine many times. I have a very large and very nice example of a pliosaur tooth from that layer. It is from a Polyptychodon if I remember correctly. The first vert looks a lot more like a pliosaur vert to me than either a plesiosaur or dinosaur vert. The second one is harder for me to help with. It does sort of look like a plesiosaur or pliosaur caudal vert. But I am much less certain about it. I have to get to work but I can show an image of the tooth tonight if I can remember it.

[Regg Cato]

Protohadros is from the Woodbine Formation, but the age effectively rules out Ceratopsian. I still maintain plesiosaur/pliosaur is the most likely identification.

[Ramo]

Nice epipodial!!

The epipodial is kind of flat in cross section not round like the one you are trying to ID.

Ramo

[jpc]

The first bone looks plesiosurian to me. See those little holes at the bottom... that screams plesiosaur. I'm not sure if hadr and ceratopsian caudals have those holes. And late K is fine for plesiosaurs.

[wfrr]

Once again an excellent discussion regarding finds very close to home. I have only found a couple of plesiosaur verts. Both of them were discovered along the eagleford of north Texas. They were exciting finds for me.

So far I have done very little poking around in the woodbine but that is going to change this winter. I intend to find my first dino material. That would really be exciting. I like learning what dino goodies are being found here in north Texas.