New paper out today in PeerJ: Lei R, Tschopp E, Hendrickx C, Wedel MJ, Norell M, Hone DWE. 2023. Bite and tooth marks on sauropod dinosaurs from the Morrison Formation. PeerJ 11:e16327 http://doi.org/10.7717/peerj.16327 This one had a long gestation.

Western University of Health Sciences

Matt Wedel

::: {.mceTemp}
 
:::

::: {#attachment_21361 .wp-caption .aligncenter shortcode="caption" style="width: 1034px"}
[![](https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=480){.wp-image-21361
.size-large aria-describedby="caption-attachment-21361" loading="lazy"
attachment-id="21361"
permalink="http://svpow.com/2023/11/14/new-paper-theropod-bite-marks-on-morrison-sauropod-bones/bitten-apatosaurus-ischium-mwc-4011-distal-end-close/"
orig-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg"
orig-size="4032,3024" comments-opened="1"
image-meta="{\"aperture\":\"0\",\"credit\":\"\",\"camera\":\"\",\"caption\":\"\",\"created_timestamp\":\"0\",\"copyright\":\"\",\"focal_length\":\"0\",\"iso\":\"0\",\"shutter_speed\":\"0\",\"title\":\"\",\"orientation\":\"0\"}"
image-title="Bitten Apatosaurus ischium MWC 4011 distal end close"
image-description="" image-caption=""
medium-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=300"
large-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=1024"
width="480" height="360"
srcset="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=480 480w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=960 960w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=150 150w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=300 300w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg?w=768 768w"
sizes="(max-width: 480px) 100vw, 480px"}](https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-distal-end-close.jpg)

Distal end of MWC 4011, an ischium of *Apatosaurus louisae* that got
munched on by a large theropod, probably *Allosaurus* or *Ceratosaurus*.
On display at Dinosaur Journey in Fruita, Colorado.
:::

New paper out today in PeerJ:

[Lei R, Tschopp E, Hendrickx C, Wedel MJ, Norell M, Hone DWE. 2023. Bite
and tooth marks on sauropod dinosaurs from the Morrison Formation. PeerJ
11:e16327
http://doi.org/10.7717/peerj.16327](https://peerj.com/articles/16327/)

This one had a long gestation. The earliest trace I can find of it in my
Gmail archive is this bit I sent Dave Hone back in February of 2015:

> Sorry to not have gotten around to sending the sauropod bite mark
> stuff. I still have the note in my phone, I'll get on it ASAP. 

I have no idea what earlier conversation that was referencing ---
wherever it happened, my end of it apparently wasn't in Gmail. I also
apparently did not follow through, because on April 26, 2018, Dave wrote
to me, "I'm vaguely trying to resurrect a survey of sauropod bite
marks," referencing that 2015 message.

At that point I did actually kick into gear and started sending him
photos and refs. Which is how, about a month later, he sent one of
kindest messages I've ever received:

> This is starting to get silly, you've already turned up more examples
> than I've managed and you've also provided papers and photos too!
> Bearing that in mind, it seems ridiculous not to formally invite you
> in on this --- are you up for continuing to supply some Morrison
> sauropod bites?

At that point I was the third on the project, with Dave and Emanuel.
Later Mark Norell, Christophe Hendrickx, and Roberto Lei would join us,
with Christophe serving as our resident theropod tooth expert, and
Roberto in particular doing a lot of the heavy lifting of turning our
findings into a paper.

::: {#attachment_21363 .wp-caption .aligncenter shortcode="caption" style="width: 1034px"}
[![](https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=480){.wp-image-21363
.size-large aria-describedby="caption-attachment-21363" loading="lazy"
attachment-id="21363"
permalink="http://svpow.com/2023/11/14/new-paper-theropod-bite-marks-on-morrison-sauropod-bones/bitten-apatosaurus-ischium-mwc-4011-oblique/"
orig-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg"
orig-size="4000,2500" comments-opened="1"
image-meta="{\"aperture\":\"0\",\"credit\":\"\",\"camera\":\"\",\"caption\":\"\",\"created_timestamp\":\"0\",\"copyright\":\"\",\"focal_length\":\"0\",\"iso\":\"0\",\"shutter_speed\":\"0\",\"title\":\"\",\"orientation\":\"0\"}"
image-title="Bitten Apatosaurus ischium MWC 4011 oblique"
image-description="" image-caption=""
medium-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=300"
large-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=1024"
width="480" height="300"
srcset="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=480 480w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=960 960w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=150 150w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=300 300w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg?w=768 768w"
sizes="(max-width: 480px) 100vw, 480px"}](https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-ischium-mwc-4011-oblique.jpg)

The rest of MWC 4011.
:::

So what's the upshot? For one, a few good-sized sauropod elements are
bitten through, showing that at least some Morrison theropods were
capable of inflicting real damage on big bones. So right off the bat we
have a survivorship problem: in a collections-based survey like the one,
we can only tally bite marks on bones that survived being bitten in good
enough shape to be collected and identified as sauropod bones. Bones
that were consumed by theropods, or shattered beyond the ability to be
preserved, recognized, or collected, are not available to us.\* In other
words, we can only tally bones in the "Goldilocks zone" of being
*directly chomped on but not too much* --- careful bites that stripped
meat from a bone without biting in are invisible, and so are bites so
violent or forceful that they destroyed the bone. This is sort of like
the osteological paradox in paleopathology (see [this
post](https://svpow.com/2022/02/19/sauro-throat-part-4-the-osteological-paradox/)),
just applied to individual bones instead of individual animals.

\*In a field-based study, it's possible to partially offset this by
collecting and analyzing *everything*, not just the identifiable bits.
Julia McHugh and colleagues did exactly that in their "nugget bucket"
study (McHugh et al. 2023), an IMHO brilliant follow-up to their papers
on theropod feeding traces (Drumheller et al. 2020) and invertebrate
feeding traces (McHugh et al. 2020) on dinosaur bones from the
Mygatt-Moore Quarry. One reason I'm so happy that Julia is at Dinosaur
Journey is that she keeps thinking of interesting stuff to do with that
collection.

I've [argued
before](https://svpow.com/2016/02/18/dinosaur-life-histories-are-plicomcated/#comment-141177)
that baby sauropods left few bones because most of them either grew up,
or --- vastly more commonly --- got processed into theropod poop. I felt
like that quip was coming back to haunt me in this project; I find it
perversely difficult to think clearly about evidence that I never get to
see!

::: {#attachment_21371 .wp-caption .aligncenter shortcode="caption" style="width: 1034px"}
[![](https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=480){.wp-image-21371
.size-large aria-describedby="caption-attachment-21371" loading="lazy"
attachment-id="21371"
permalink="http://svpow.com/2023/11/14/new-paper-theropod-bite-marks-on-morrison-sauropod-bones/bitten-apatosaurus-pubis-mwc-861/"
orig-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg"
orig-size="4000,2500" comments-opened="1"
image-meta="{\"aperture\":\"0\",\"credit\":\"\",\"camera\":\"\",\"caption\":\"\",\"created_timestamp\":\"0\",\"copyright\":\"\",\"focal_length\":\"0\",\"iso\":\"0\",\"shutter_speed\":\"0\",\"title\":\"\",\"orientation\":\"0\"}"
image-title="Bitten Apatosaurus pubis MWC 861" image-description=""
image-caption=""
medium-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=300"
large-file="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=1024"
width="480" height="300"
srcset="https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=480 480w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=960 960w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=150 150w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=300 300w, https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg?w=768 768w"
sizes="(max-width: 480px) 100vw, 480px"}](https://svpow.files.wordpress.com/2023/11/bitten-apatosaurus-pubis-mwc-861.jpg)

MWC 861, a pubis of *Apatosaurus louisae* with an extensively bitten
distal end. Definitely from the same quarry as MWC 4011 --- the
Mygatt-Moore Quarry, in far western Colorado --- and possibly from the
same individual. Also on display at Dinosaur Journey.
:::

Interestingly, we found zero examples of healed bites on Morrison
sauropod bones. So all of the bite marks we found were either from
successful predation events, or scavenging. And in fact we didn't find
that many bitten sauropod bones, period. We found 68 Morrison sauropod
bones with bite marks, out of the 600 or so that we actively surveyed.
That's about 11%, compared to 14% in later tyrannosaur-dominated faunas
(Jacobsen 1998). But also, we found a lot of wear on the teeth of large
Morrison theropods, which suggests that they were processing tough
stuff, including bones.

We suspect that big Morrison theropods were primarily targeting juvenile
and subadult sauropods, and scavenging dead adults when they could get
them. We think that partly because younger sauropods must have been more
numerous than adults (and maybe *vastly* more numerous), and partly
because almost all predators prefer easy fights to difficult ones. As I
wrote [back
when](https://svpow.com/2016/02/27/giant-oklahoma-apatosaurus-mount-from-above/#comment-141485),

> Even assuming that max-sized individuals were around -- which may not
> always have been the case... -- the theropods would have to walk right
> past a whole boatload of smaller, easier targets to get to them,
> ignoring winnable fights and achievable calories just to roll the dice
> in the most dangerous possible encounters.

Naturally Dave has explored a lot of these ideas in his previous papers,
especially Hone and Rauhut (2010) --- this new paper is basically a
spiritual successor to that one. Dave has his own blog post up about the
new paper,
[here](https://archosaurmusings.wordpress.com/2023/11/14/theropods-bit-sauropods-too/). 

::: {#attachment_21368 .wp-caption .aligncenter shortcode="caption" style="width: 1034px"}
[![](https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=480){.wp-image-21368
.size-large aria-describedby="caption-attachment-21368" loading="lazy"
attachment-id="21368"
permalink="http://svpow.com/2023/11/14/new-paper-theropod-bite-marks-on-morrison-sauropod-bones/galeamopus_scenab_v2_davide_bonadonna/"
orig-file="https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg"
orig-size="7480,4251" comments-opened="1"
image-meta="{\"aperture\":\"0\",\"credit\":\"\",\"camera\":\"\",\"caption\":\"\",\"created_timestamp\":\"0\",\"copyright\":\"\",\"focal_length\":\"0\",\"iso\":\"0\",\"shutter_speed\":\"0\",\"title\":\"\",\"orientation\":\"1\"}"
image-title="Galeamopus_scenaB_V2_Davide_Bonadonna" image-description=""
image-caption=""
medium-file="https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=300"
large-file="https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=1024"
width="480" height="273"
srcset="https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=480 480w, https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=960 960w, https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=150 150w, https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=300 300w, https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg?w=768 768w"
sizes="(max-width: 480px) 100vw, 480px"}](https://svpow.files.wordpress.com/2023/11/galeamopus_scenab_v2_davide_bonadonna.jpg)

*Allosaurus* munching on a dead *Galeamopus* while a pair of ceratosaurs
look on hungrily. Art courtesy of Davide Bonadonna
([www.davidebonadonna.it](http://www.davidebonadonna.it))
:::

Theropods primarily attacking small sauropods would explain the patterns
that we see, better than any alternative we can think of. Of course the
Morrison covers a lot of space and time, and [animals do all kinds of
weird
stuff](https://svpow.com/2011/11/28/accurate-vs-familiar-vs-usual-in-paleoart/)
if you watch them long enough, including suicidal attacks on much larger
prey. But if theropods were preferentially attacking adult sauropods,
we'd expect to see at least some healed bite marks from failed attacks,
and we'd also expect to see more bite marks, period. Somehow big
Morrison theropods were managing to put a lot of wear on their teeth
without leaving many tooth-marked sauropod bones behind, which seems
like a big mismatch. The best explanation we can think of is that the
theropods were accumulating that wear munching on juvenile sauropods
(which we thought they were doing anyway), and consuming or destroying
their bones in the process (which the theropods were well-equipped to
do).

But even if we're right, there's a ton we don't know yet. We struggled
to match any of the bite marks that we found to specific theropod taxa.
Taphonomy and collector bias are probably both big filters, especially
for bones that were bitten through or shattered before fossilization.
There are definitely important differences between quarries --- for
example, Mygatt-Moore has a ton of bitten bones, and the Carnegie Quarry
at Dinosaur National Monument has almost none, and we don't know why.

In sum, there's a lot to do, with interesting, tractable, as-yet-undone
projects surrounding this paper in a quantum fuzz like an electron
shell. Hopefully other folks will get out there and start turning those
potential projects into real ones.

::: {#attachment_21366 .wp-caption .aligncenter shortcode="caption" style="width: 1034px"}
[![](https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=480){.wp-image-21366
.size-large aria-describedby="caption-attachment-21366" loading="lazy"
attachment-id="21366"
permalink="http://svpow.com/2023/11/14/new-paper-theropod-bite-marks-on-morrison-sauropod-bones/wedel-rocks-dinos/"
orig-file="https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg"
orig-size="2700,2700" comments-opened="1"
image-meta="{\"aperture\":\"0\",\"credit\":\"\",\"camera\":\"\",\"caption\":\"\",\"created_timestamp\":\"0\",\"copyright\":\"\",\"focal_length\":\"0\",\"iso\":\"0\",\"shutter_speed\":\"0\",\"title\":\"\",\"orientation\":\"0\"}"
image-title="Wedel rocks dinos" image-description="" image-caption=""
medium-file="https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=300"
large-file="https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=1024"
width="480" height="480"
srcset="https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=480 480w, https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=960 960w, https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=150 150w, https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=300 300w, https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg?w=768 768w"
sizes="(max-width: 480px) 100vw, 480px"}](https://svpow.files.wordpress.com/2023/11/wedel-rocks-dinos.jpg)

MWC 4011, once more with feeling. And fiberglass. Photo by Brian Engh.
:::

## References

- [Drumheller, S.K., McHugh, J.B., Kane, M., Riedel, A. and D'Amore,
  D.C. 2020. High frequencies of theropod bite marks provide evidence
  for feeding, scavenging, and possible cannibalism in a stressed Late
  Jurassic ecosystem. PLoS One 15(5)
  p.e0233115.](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233115)
- [Hone, D.W. and Rauhut, O.W. 2010. Feeding behaviour and bone
  utilization by theropod dinosaurs. Lethaia 43(2):
  pp.232-244.](https://www.idunn.no/doi/pdf/10.1111/j.1502-3931.2009.00187.x)
- Jacobsen AR. 1998. Feeding behaviour of carnivorous dinosaurs as
  determined by tooth marks on dinosaur bones. Historical Biology
  13:17--26. DOI 10.1080/08912969809386569.
- [McHugh, J.B., Drumheller, S.K., Riedel, A. and Kane, M. 2020.
  Decomposition of dinosaurian remains inferred by invertebrate traces
  on vertebrate bone reveal new insights into Late Jurassic ecology,
  decay, and climate in western Colorado. PeerJ 8,
  p.e9510.](https://peerj.com/articles/9510/)
- Mchugh, J.B., Drumheller, S.K., Kane, M., Riedel, A. and Nestler,
  J.H. 2023. Assessing paleoecological data retention among disparate
  field collection regimes: a case study at the Mygatt-Moore Quarry
  (Morrison Formation). Palaios 38(5):233-239.

 

------------------------------------------------------------------------

[doi:10.59350/txkht-ewp95](https://doi.org/10.59350/txkht-ewp95)


New paper: theropod bite marks on Morrison sauropod bones

In the last post I pointed out some similarities between Davide Bonadonna’s new

Spinosaurus

 painting and Brian Engh’s

Spinosaurus

 painting from 2010.

Guest post: the genesis of Davide Bonadonna’s Spinosaurus painting

**UPDATE the next day:** Since I published this post, it's become clear
that the similarities in the two images are in fact convergence. Davide
Bonadonna got in touch with Mike and me, and he has been very gracious
and conciliatory. In fact, he volunteered to let us post the making-of
images for his painting, which I will do shortly. I'm sorry that my
initial post was more inquisitorial than inquisitive, and implied
wrongdoing on Davide's part. Rather than edit it out of existence, I'm
going to let it stand as a cautionary signal to my future self. Stand by
for the new post as soon as I can get it assembled and
published....aaaand [here it
is](http://svpow.com/2014/09/16/guest-post-the-genesis-of-davide-bonadonnas-spinosaurus-painting/).

-------

Scott Hartman has already
[explained](http://www.skeletaldrawing.com/home/theres-something-fishy-about-spinosaurus9112014)---[twice](http://www.skeletaldrawing.com/home/there-may-be-more-fishiness-in-spinosaurus9132014)--that
the super-short-legged, "*Ambulocetus*-grade" *Spinosaurus* from the new
Ibrahim et al. (2014) paper has some major problems. Those are both
good, careful, thought-provoking posts and you should go read them.

I'm writing about something else fishy with the "new" *Spinosaurus* and,
in particular, National Geographic's media push. Let's check out this
life restoration, newly prepared for the *Spinosaurus* story:

[![Spinosaurus - Nat
Geo](https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=480&h=247){.aligncenter
.size-full .wp-image-10782 loading="lazy" attachment-id="10782"
permalink="http://svpow.com/2014/09/15/spinosaurus-fishiness-part-n/spinosaurus-nat-geo/"
orig-file="https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg"
orig-size="1600,826" comments-opened="1"
image-meta="{\"aperture\":\"0\",\"credit\":\"\",\"camera\":\"\",\"caption\":\"\",\"created_timestamp\":\"0\",\"copyright\":\"\",\"focal_length\":\"0\",\"iso\":\"0\",\"shutter_speed\":\"0\",\"title\":\"\",\"orientation\":\"0\"}"
image-title="Spinosaurus – Nat Geo" image-description=""
image-caption=""
medium-file="https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=300"
large-file="https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=1024"
width="480" height="247"
srcset="https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=478&h=247 478w, https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=957&h=494 957w, https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=150&h=77 150w, https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=300&h=155 300w, https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg?w=768&h=396 768w"
sizes="(max-width: 480px) 100vw, 480px"}](https://svpow.files.wordpress.com/2014/09/spinosaurus-nat-geo.jpg)

And now let's look at this one by Brian Engh from a couple of years ago,
borrowed from Brian's [art
page](http://dontmesswithdinosaurs.com/?page_id=13):

[![Spinosaurus KemKem - Brian
Engh](https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=480&h=257){.aligncenter
.size-full .wp-image-10783 loading="lazy" attachment-id="10783"
permalink="http://svpow.com/2014/09/15/spinosaurus-fishiness-part-n/spinosaurus-kemkem-brian-engh/"
orig-file="https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg"
orig-size="1008,540" comments-opened="1"
image-meta="{\"aperture\":\"0\",\"credit\":\"\",\"camera\":\"\",\"caption\":\"\",\"created_timestamp\":\"0\",\"copyright\":\"\",\"focal_length\":\"0\",\"iso\":\"0\",\"shutter_speed\":\"0\",\"title\":\"\",\"orientation\":\"0\"}"
image-title="Spinosaurus KemKem – Brian Engh" image-description=""
image-caption=""
medium-file="https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=300"
large-file="https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=1008"
width="480" height="257"
srcset="https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=480&h=257 480w, https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=960&h=514 960w, https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=150&h=80 150w, https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=300&h=161 300w, https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg?w=768&h=411 768w"
sizes="(max-width: 480px) 100vw, 480px"}](https://svpow.files.wordpress.com/2014/09/spinosaurus-kemkem-brian-engh.jpg)

And let's count up the similarities:

- Two spinosaurs, one in the foreground with its head mostly or entirely
  submerged as it bites a fish, and one further back on the right with
  its head complete out of the water;
- Two turtles, one in the foreground with its head out of the water, and
  one further back on the right fully submerged;
- A good diversity of fish swimming around in the foreground;
- Pterosaurs flying way back in the background;

And finally, and most interestingly to me:

- A curved-water-surface, fish-eye perspective to the whole scene.

All the bits are moved around a bit, but pretty much everything in
Brian's picture is in the new one. Is it all just a big coincidence--or
rather, a fairly lengthy *series* of coincidences? Seems unlikely. Your
thoughts are welcome.


UPDATE the next day:

Since I published this post, it’s become clear that the similarities in the two images are in fact convergence. Davide Bonadonna got in touch with Mike and me, and he has been very gracious and conciliatory. In fact, he volunteered to let us post the making-of images for his painting, which I will do shortly.

Messages de Rogue Scholar

New paper: theropod bite marks on Morrison sauropod bones

Guest post: the genesis of Davide Bonadonna’s Spinosaurus painting

Spinosaurus fishiness, part n