Roberta: The other brachylophosaur

Hello again – from Houston this time. Steven and I are back from Malta. It’s been a few days since we’ve posted about the trip. I’m not gonna lie – we were tired, y’all. People always ask what it takes to be a paleontologist – in addition to education and field experience, it  also takes a lack of need for any kind of sleep. It’s a completely amazing experience, but they get up at 6 a.m. and they don’t go to sleep until after midnight – and that’s a long day of hiking up mountains and hanging off cliffs.

So, apologies for the delay, but we have lots more to share – starting with Roberta, the other brachylophosaur. (Besides Leonardo, that is.) She’ll be on display in the new Great Plains Dinosaur Museum (opening June 6 in Malta, MT – book your tickets now. Seriously – you won’t be disappointed), so she won’t be on display in Houston with Leonardo – but she’s a beautifully preserved specimen (as you can see), and we got the chance to see the process of preservation in action this week.

Leonardo and Roberta

A full size model of Leonardo stands over Roberta, another brachylophosaur found near Malta. Though she does not have skin, Roberta is extremely well preserved. It’s very rare to find a dinosaur so complete. Normally, display specimens are pieced together from multiple individuals.
In the background, several paleontologists are working on other specimens housed in the Field Station.

Roberta’s broken nose

Roberta’s nose was broken in life – which would have made it very difficult for her
to eat. Her species processed tough plant material by grinding the top part of their
skull over the bottom part – so a break like this would have severely
impeded that process.

Roberta’s teeth

Roberta’s teeth are so well preserved, you almost want to brush them.

Roberta’s ribs

Roberta’s ribs are resting on the plaster jacket in which she was carried
out of the excavation site (see the gap?). Looking at the skeleton from the
top, the bones appear to be stuck to the jacket – in fact, many pieces had
to be removed before the specimen could be driven to the new Museum.
Otherwise, the vibration from the drive could have jiggled them apart.

The fossils have been preserved in the ground for millions of years – but once you get them out, it’s important to retain that preservation. Montana is so dry that once the bones have been excavated, they can dry out, crack and fall apart very easily. So, every six months, a new coat of Vinac (essentially, glue) must be applied to prevent this from happening.

In this video, Kathy Zoehfeld Vinacs (yes, it’s one of those noun-verbs, like “Google”) Roberta’s skull, to stabilize the fossil before the move to the new museum.

You can see David prepping the other end of Roberta’s skeleton here. In each video, notice how the Vinac adds a visible, thin sheen, in comparison to the other bones that haven’t been coated yet. It soaks into all the pores and helps stabilize the bones, so they don’t begin to crumble.

More soon on Dak – the brachy that survived a T. rex attack!

3 thoughts on “Roberta: The other brachylophosaur

  1. Hi Nick,

    I believe you are correct – that evidence of healing is what has told them that the bone was broken in life. But, I’ve e-mailed our paleontologists to get you a more specific answer; I’ll post it here as soon as I can.

    On another note – Dak, the fossil I mention at the end of my post has some spectacular, very obvious healing present. I’ll be posting photos and more info soon.

    Thanks for commenting!

  2. Hi again, Nick,

    I have two answers for you – the first is from Mark Thompson, a paleontologist that has been working in the area since before Leonardo was discovered:

    “Yes, the broken nasal bones show evidence of healing, re-growth of bone along the fractures.

    This is the evidence for the damage being done when Roberta was alive, not post-mortem, and that she survived for some time afterwards.

    My personal estimate is about a month, which is both how long it would take to show that type of bone healing and also how long she may have survived without food before starving to death.

    We don’t know yet what caused her death ultimately. She may have starved to death, or infection associated with the injury impacted her brain. Other thoughts are that Roberta’s nasal injury impacted on her ability to feed, so causing a loss of condition, making her succumb easier to exposure or predators.”

    Dr. Bakker, who has also been involved with the Leonardo project since the beginning, was in Malta last week with Mark, and is the curator of the exhibition we are developing, also sent an answer to your query:

    “Roberta’s muzzle is strange. There are thinned-out zones, curiously granular bone texture, and separation lines that cross through single bones. All very different from conditions we see in the adult skull ‘Elvis’ and the juvenile ‘Peanut.’

    We need hi-res CT-Scans to investigate the cause of the damage – right now the breaks do not look like the usual effects of post-mortem scavenging, weathering and crushing that results from heavy layers of sand piling on top of a skeleton.

    Brachys seem to show a higher frequency of injuries inflicted in life than other duck-bills. ‘Peanut’ had anterior tail vertebrae infected and fused by diseased bone, a condition common in theropod carnivores but rare in herbivores. We have a third specimen that recovered from a severe bite across the rump.

    The dinosaur mummy show will display yet another Early Judithian hadrosaur with spectacular bite marks – in this case the bite may have been part of a fatal attack.”

    I hope these responses from Dr. Bakker and Mark answer your questions; Mark also asked if anyone reading has a good way of testing these hypotheses further, he’d be very glad to read it here – so leave us a comment if you have an idea.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>