Sabertooth diaries 1: excavating old sketches by Mauricio Antón

“As the publication of my book  ”Sabertooth” comes closer, I am trying to put some order in the mass of material I have been working with during the last few years. It is interesting to leaf through those fat folders full of sketches, some of them dating from MANY years ago: it refreshes my memory about some of the main subjects I have dealt with in the book, and in fact, it motivates me to tackle some of these subjects again, in anticipation for the next book (title to be disclosed at some point in the future…).

Here are some of those “paleo-sketches” (in the whole sense of the word!). They date from more than 15 years ago (Gosh!) and were  my early attempts to put together observations about key aspects of big cat anatomy, especially related to hunting…(these drawings do not appear in the book or anywhere else  in this form, so this is a sort of exclusive…)

In the years after I did these sketches I have found many fascinating things about these aspects of felid anatomy, which I have tried to reflect in the new book. These days I am preparing a short video about some of these things, I expect to be posting it soon!”

  • First image: “compares the “primitive” skeletal porportions of the early cat Pseudaelurus (left) with those of the very different cheetah (Acinonyx) and sabertooth (Smilodon). Obviously, the skeletons and cats are not shown to scale”
  • Second image: “shows aspects of the anatomy of the cheetah, with special attention to the lumbar vertebrae.  For the fun of it, I also included a body size comparison betwen the modern cheetah and the extinct species Acinonyx pardinensis.  Back then I was already puzzled by the possible meaning of the changes in body proportions during the evolution of sabertooths, and in particular in the shortening of the lumbar vertebra in many species”
  • Third image: “shows the sequence of events during a hypothetical hunt by the sabertooth Smilodon: the chase (top); the wrestling struggle (middle); and the killing bite (bottom)”
  • Fourth image: “shows the crucial point when the cat attempts to pull a large prey down to the ground, and it highlights some of the muscles relevant for that action”

(Image and text source: Chasing Sabretooths; via @Laelaps on Twitter)

anonymous asked:

Regarding that post about All Yesterdays, isn't it backwards to reconstruct a baboon without using primate references? By using "modern principles of dinosaur reconstruction" on something that is not a dinosaur would produce false and inaccurate results. Reconstruction artists actually use references from modern birds because they are closely related to dinosaurs.

This I can answer in a pinch and I would agree.  Yes, indeed if we were to base the reconstruction of any animal upon a taxon from which it diverged millions of years ago, it would be really difficult to arrive at a finished product resembling anything at all like that of the intended animal.

As I understand it the point of the post and the book as a whole is to point out that we can’t know exactly what a fossil species looked like.  For example, organic material rarely preserves. We can look to skeletal morphology and to descendent taxa for clues but an exact reconstruction that we can be 100 per cent confident about is impossible. So, for example, if you decide to add strong musculature around the cheeks to, I don’t know, say a sagittal crest, based upon rugosity on the mandible, you’re making an educated guess. Or if for example you include feathers on a dinosaur taxon based upon its phylogenetic relationship to birds, you’re making an educated guess as well but that guess could be wrong. Would it have penguin-like feathers or peacock-like feathers? What aspects of the fossil can we look at to infer what sort of feathers if any feathers it had? 

Basing a baboon upon a dinosaur is just an extreme example, which I believe was probably used for effect, to make a point. I haven’t read this book so I can’t be sure. The authors note in the article that they aren’t arguing that reconstructions are arbitrary but that certain aspects of certain reconstructions of certain taxa are less informed:

“What we do say in the book (and as I said in my talk) is that while the positions of muscles might be known (or reasonably inferred), their size is typically something we can’t be so sure about. Hence we now have fat-tailed theropods (Persons & Currie 2011) – as opposed to the slimmer-tailed ones produced by Bakker and Paul – and also a degree of leeway as goes how chunky and how muscular animals like Tyrannosaurus might have looked overall (Hutchinson et al. 2011)”.

In using the baboon-dinosaur as an example, they are not only being intentionally creative, as is part of the point of the book, (and hyperbolic in this instance), but are also highlighting, I believe, the need to base palaeoillustrations, that they think have become ossified in canon, upon known myology and osteology. If you don’t do your job properly, get stuck in what is assumed and/or infer phylogeny poorly and/or don’t read the fossils correctly, you could end up with something like what you legitimately took issue with—a baboon based on a dinosaur.