Thursday, April 6, 2017

Theropods or Tender-pods? The Softer Side of the "Terrible Lizard."

Nature, red in tooth and claw...

It's the common image associated with theropod dinosaurs: they are either chasing something down to eat it, or they are eating it. Every lazy bit of sad science storytelling depicts theropods consumed with one objective: devouring poor innocent plant-eating prey. From Lex asking "Where's the goat?" in Jurassic Park to Littlefoot's mom being killed by Sharptooth, theropods (and all carnivores, really) get painted with the "evil" brush and brushed off as mindless killers.

It's still too soon for me to post Littlefoot's mom's death.
Logically we know that theropods were more than just heartless (our words and judgement) killing machines. Theropod dinosaurs were and still are animals with a complex suite of behaviors that we would anthropomorphize as "tender" and "gentle."

We know that theropods built nests and incubated their young: research by Tanaka et al. (2015) demonstrated the different nesting strategies that dinosaurs used based on egg shell porosity. Egg shell is not solid: it is full of tiny pores that allow for moisture and gas exchange to happen between the egg and its environment. Based on modern nesting crocodiles and birds, the more porous eggshell is, the more likely it was that the eggs would be completely buried in a nest mound. Less porous eggs would only be partially buried with the upper surfaces of the eggs exposed. Maniraptoran theropods (dromaeosaurs, oviraptors, troodons, and our modern birds) have low porosity eggs, which would be partially exposed in the nest.

Maniraptoran theropods are well-known for another tender-loving trait: incubating eggs. Several fossil nests have been recovered with a maniraptoran caught in the act of brooding. The spectacular specimen of Citipati, an oviraptorosaur, on top of a nest of eggs is on display at the American Museum of Natural History. This is a good example of parental care in theropods.

We know that theropods (at least the maniraptorans) engage(d) in nest building and egg brooding behavior...but what about the pre-nesting activities, like courtship? Our modern theropods are famous for their courtship behaviors. Check out the mating dance of the Flame Bowerbird...



...and now imagine Oviraptor doing this dance.

"Hold up! There should be evidence of male theropods having some skeletal differences that can be used to support possible mating dances, right? Right!?!"

Using the skeleton alone, the best way to tell if a theropod skeleton was male or female is to look for a structure called medullary bone: it's a special deposit in the hollow portion of theropod bones that acts as a calcium reserve for adding shells to eggs. Medullary bone is only going to occur in egg-laying (female) theropods. However, medullary bone is an internal structure: you can't tell by looking at the exterior of a bone whether it contains medullary bone.

While there have been a few - quite a few - papers published that purportedly contain evidence of skeletal sexual dimorphism (anatomical differences in the skeleton) in dinosaurs (the most recent one uses a small sample size of tails of oviraptorosaurs) the numbers simply do not support that the differences seen are the result of sexual differences, as opposed to good ol' natural variation. An excellent study by Dr. Jordan Mallon was recently published that rigorously tests the statistics of all of the proposed cases of sexual dimorphism that involve visual differences in bones...and no evidence of sexual dimorphism was found in any of the cases. Internal eggs, embryos, and medullary bone are still the only way to confidently identify the sex of a dinosaur.

So, are there any fossils that possibly support courtship activities in theropods? We may have fossils in the form of trace fossils...ichnology to the rescue! In 2016 we published on these enigmatic traces from the Early Cretaceous of Colorado. They are paired scrape marks made by the feet of large theropods (likely an allosaur.) No tracks led up to any of the scrape marks, showing us that the theropods dug down through the layer they were walking on.

Figure 1 from Lockley et al. (2016) showing the scrape marks.
Figure 3 from Lockley et al. (2016).

These marks were a puzzle at first. We initially thought that the trackmakers were digging for water, but the geology of the area showed that water was active and abundant. Next we considered that they were digging for food, but the sandy layer the theropods were digging down to was devoid of traces of most burrowing animals. Next we considered nest bowls and/or dust bathing. Both activities, like rooting around for food, tend to wipe out the marks made by digging (based on what we've seen with dust bowls made by Spruce and Ruffed grouse in our area.)

Ruffed Grouse dust bathing, Jose Schell.
Then we considered territory marks. The closest modern example we could find of a convincing territory mark came from mountain lions. Check out this blog for some excellent pictures of the paired scrapes left by mountain lions.

This led us to consider the different reasons a theropod would make a visible territory mark...and then we came across the nest scrape ceremony.

Check out this video of the Piping Plover nest scrape ceremony (and because I love plovers, check out the Great Lakes Piping Plover Recovery Project.)


Also see this video of a Killdeer nest scrape ceremony. I know where Killdeer were nesting locally last year, so I'm hoping to get some of my own footage this spring.


To start the nest scrape ceremony, the male will define and defend their territory. They vocalize to nearby females, and demonstrate to them how good they are at digging out nests. A male may perform and create several nest scrapes during the pre-mating ceremony. If the female is satisfied with his performance, she allows the male to mate. One of the nest scrapes becomes the nest bowl.

There is a good chance that our large theropods were engaging in a courtship ceremony that involved scraping at the ground. It is not uncommon to have multiple males displaying in one location: game birds are a great example with their display arenas or leks, like the Greater Prairie Chicken.




Of course, we had to come up with an Early Cretaceous version of a theropod lek...
Figure 6 of Lockley et al. (2016). Yes, those theropods in the background are doing exactly what you think they are doing.

Recently a paper by Carr et al. (2017) published on the facial scales of the tyrannosaurid Daspletosaurus horneri (a new species) that has skeletal evidence of not just scales on its face, but very sensitive facial scales. How sensitive? These scales were likely more sensitive to touch than human fingertips. Why would a tyrannosaur have such a sensitive snout? I'll let the authors speak to that:

"ISOs [integumentary sensory organs] would have aided adult tyrannosaurids in harmlessly picking up eggs and nestlings and, in courtship, tyrannosaurids might have rubbed their sensitive faces together as a vital part of pre-copulatory play." (Carr et al., 2017)

We now have more than enough evidence to abandon the tired cliche of the one-dimensional killing machine image of theropod dinosaurs. Extinct theropods were just as multifaceted and complex as any of our modern theropods or animals that we see today. A carnivorous animal is not simply a vicious slaughterhouse on legs and wings: they attract mates and care for the young that they produce. The fact that they eat meat to support these tender activities should be free of judgement on our part. We should learn to appreciate all aspects of a carnivore's life and pass that appreciation on to the next generations.

While you are here, I highly recommend peeking into the tender lives of our modern theropods by watching live nest cams! Here are links to the nest cam I frequent. Most are nest cams of birds of prey, so you will see prey either in the nest or being brought to the nest.

Barred Owl: http://cams.allaboutbirds.org/channel/43/Barred_Owls/

Savannah Osprey: http://cams.allaboutbirds.org/channel/54/Savannah_Ospreys/

Laysan Albatross: http://cams.allaboutbirds.org/channel/41/Laysan_Albatross/

Peregrine Falcon: http://explore.org/live-cams/player/peregrine-falcon-cam

Bald Eagle: http://explore.org/live-cams/player/decorah-eagles-north-nest

Great Blue Heron: http://explore.org/live-cams/player/great-blue-herons-chesapeake-conservancy

Hummingbirds (there are babies in the nest right now!) http://explore.org/live-cams/player/rosie-hummingbird-nest

Enjoy!

References

Carr TD, Varricchio DJ, Sedlmayer JC, Roberts EM, Moore JR (2017) A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system. Scientific Reports 7, Article number: 44942 (2017) doi:10.1038/srep44942

Lockley MG*, McCrea RT, Buckley LG, Lim JD, Matthews NA, Breithaupt BH, Houck KJ, Gierlinski GD, Surmik D, Kim KS, Xing L, Kong D-Y, Cart K, Martin J, Hadden G. 2016. Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behavior by Cretaceous dinosaurs. Scientific Reports 6:1–10

Mallon JC. 2017. Recognizing sexual dimorphism in the fossil record: lessons from nonavian dinosaurs. Paleobiology, doi: 10.1017/pab.2016.51

Persons SW IV, Funston GF, Currie PJ, Norell MA (2015) A possible instance of sexual dimorphism in the tails of two oviraptorid dinosaurs. Scientific Reports 5, Article number: 9472 (2015) doi:10.1038/srep09472

Tanaka K, Zelenitsky DK, Therrien F (2015) Eggshell Porosity Provides Insight on Evolution of Nesting in Dinosaurs. PLoS ONE 10(11): e0142829. doi:10.1371/journal.pone.0142829

Tuesday, March 21, 2017

Story-telling in Science Doesn't Mean You Make *#%& Up.

Hello Dear Readers!

I have been a busy Strange Woman lately: giving talks, visiting family, writing abstracts, collecting data for papers...you know, the usual stuff.

I've also been - rather unsuccessfully, I might add - trying to influence science communication. I was asked to review the text of a tourism information sign. The purpose of the sign was to "engage visitors and get them excited to see the dinosaur track attraction." Now, I've reviewed such signs before - mostly for our local hiking group - and they have been both interesting and factually correct. I was expecting such quality when I opened the document (done by an organization not associated with the hiking group.)

Friends, I had to check my calendar to make sure that I was not in some April Fools' Day prank.
It. Was. Bad. I won't go into all of the details of how bad it was, but here are two examples.

First, it was painfully evident that the author did not actually look into any of the public work that had been done previously on the site in question, as the dinosaurs were misidentified. We're not talking a lower specialist "Oh you're just being picky type of identification." We're talking "saying ankylosaur tracks are duck-billed dinosaur tracks" type of boo-boo. It would be akin to me saying that a cat was a bear.

Getting the visitor interested: 4/10, but only because there are theropods.
Accuracy: 5/10, but only because they got the theropods right. The rest was made-up malarkey.

Now, this site has both theropod tracks (our carnivorous dinosaurs) and ankylosaur tracks (herbivorous armored dinosaurs) preserved on the same surface. One of the first questions people tend to ask is "Were the theropods hunting the ankylosaurs?" The answer is likely not. A dinosaur track surface is like a farmer's field in the winter. You'll see all sorts of tracks: deer, coyote, dog, cat, person, snowmobile, etc., all made at different times. The surface collects these tracks over time like a doodle scratch pad next to the phone. Just because you see snowmobile tracks in the same field as a dog trackway does not mean that they were made at the same time, or that snowmobiles are viciously hunting dogs and people.

That did not stop Skippy (I needed a name for the author, since I have no idea who it is) from pulling the sadly predictable of "the vicious theropods stalking the ankylosaurs."

Getting the visitor interested: 1/10. Who hasn't heard that tired old chestnut trotted out for EVERY site with a theropod involved without any way to back it up? Snooze-ville.
Accuracy: 0/10. With no evidence to support a hunting scenario, they would be essentially lying to the visitors.

I've read and written A LOT of public education materials. I give A LOT of public talks on fossil tracks. I tweet voraciously.  Do you know what I've found out during all of this time?

1. People are interested in the facts! We have not found it that difficult to tell people accurate information about our track sites and our research and to get them excited about it. Heck, that's where most of our research funding comes from: getting non-specialists excited about the projects. We're good at this. There are lots of different groups and media outlets that do ask us to fact check, because they know we aren't going to BS them with fanciful nonsense.

2. People don't like to be patronized to. Infantilizing information, or the infamous "dumbing down," is basically telling people that they are not bright enough to appreciate the facts. Most people really do want facts when they are visiting a science place or going to a science talk - heck, that's why they are there! - and it is a direct insult to the audience if you assume that they are not going to get it unless you add nonsense. Every time we give a talk, we have an audience that is excited about hearing the newest information. They're in the know, and they end up wanting to know more.

My comments on the document were longer than the document itself. The response: "This is a method of storytelling to get people engaged."


According to Skippy, making stuff up about a science site is A-OK as long as people get interested. So Skippy, what happens when the visitors do get interested, and do their own investigations, and find out you fed them the science communication version of used tissues? Is this still engaging storytelling?


In my frustration, I took to Twitter. Here is what I posted:
That post struck a chord with people: I've never had a viral tweet, but a lot of people agreed with this approach. To me it's a sign that people are getting a bit tired of the same old insulting scicomm that marketing types and large-platform media are offering.

I cannot blame them. When a TV program, documentary, billboard, tourism brochure, marketing strategy, etc., presents a cheap and lazy science story to engage their target audience, they are not doing it from a place of respect. They are demonstrating that they do not respect either the science or their audience.

I am angry and frustrated at this lazy, disrespectful approach to science-related engagement. Anyone feeding you a sensationalized story "because it's engaging" is essentially lying to you. They don't want you to know that they think you are too thick to appreciate the facts. People should be insulted when they are presented with sloppy advertising, cringe-worthy network programming, and Barney-fied displays. You're being insulted right to your face, except the people doing the insulting get to hide behind their networks and billboards. For every "Hunting Bigfoot" show and use of Jurassic Park imagery to push dinosaurs, you are being told your interest is worth the minimal effort. They are using their large platforms to decide FOR YOU what you have the smarts to understand. If someone wearing a Big Network badge walked up to you and said "You are too dense to understand the real information," would you accept that? I hope not, and I hope you don't accept it when it's presented to you in the form of a sign, TV show, or tourism campaign.

The people who push these insulting narratives don't actually believe - or want to take the time to find out - that the facts do make a story interesting! People visit historical sites, read non-fiction biographies, and watch documentaries: they want to know what happened. People also want to know how and why we know it happened. This is no different when applied to promoting dinosaur sites and museums. We don't have to "trick" people into being excited about science, and we shouldn't ever be approaching this from a "tricking" or "sneaking in the science" perspective. Again, that doesn't come from a position of respect.

I'm in the process of collecting #SadSciPromo examples: the signs, promotions, and shows that are supposedly science-based but make you do the eternal head desk.


Do you have any examples of #SadSciPromo that you have encountered? Please let me know. The more of these that I collect - and the more people who indicate that they are fed up with this type of insulting media - the more background information I'll have to demonstrate when needed that we need to respect our audiences more than those who call marine reptiles dinosaurs, or those who think fake documentaries on mermaids are good for public science literacy. We all deserve much, much better, and should demand it.

Until next time,
Strange Woman.

Friday, January 6, 2017

SCIENCE TRACKS: Scicomm Pamphlets to Spread the Science Fun

Happy 2017, Dear Readers!

Over the holidays I was at home, minding my own business - drinking tea, working on retooling the last publishable chapter from my dissertation, watching bad paranormal TV, and acting as a heated mattress for the kitty - when there's a knock on my front door.

Lo and behold, it was a door-to-door religious solicitor. Nowadays they are fairly high-tech: rather than try to hand me a pamphlet, his opening line was presenting his tablet/iPad and saying "Now watch this video and I'm sure it will help you answer some of Life's questions." My grandparents had a sign taped to their door that read "No solicitors, religious or otherwise. We have no time, patience, or money." Needless to say, they taught me well.

My response to these types of solicitations is polite but direct: I'm an evolutionary biologist, and my questions are already answered. I caught a very brief change flicker over the guy's face - something akin to a flare of anger - but he wisely turned around and left.

Naturally, I shared my experience with my Twitter friends.


I let my mind free-associate a bit after that. I briefly thought about how funny it would be if - rather than having religious solicitors - we had science solicitors, going door-to-door spreading the Science. Of course my brain immediately jumped to "Science doesn't preach: science provides learning opportunities."


The more my brain played with the idea, the more my brain liked it.

I have completed one pamphlet for what I'm calling Science Tracks: purely scicomm pamphlets that can be used for any opportunity that arises for spreading the good word about all the awesome science that's out there. I may have been a little optimistic on getting more than one completed over the holidays. One big reason is that I don't want to use other people's photos for this without permission, and the only pamphlet I could complete using my own photos was OMFG* BIRDS! (no one who follows me is surprised), but it is a start of something that I hope to continue.
*Oh My Feathery Goodness

Here is the link to the first Science Tracks PDF, OMFG BIRDS! Hope you enjoy!

Here is a screenshot of the outside of the pamphlet:

Here's a screenshot of the inside of the pamphlet: