The Top 10 hominin #FossilFriday tweets of 2018

Another year-end list! This one is becoming an old tradition on this blog… My favorite hominin #FossilFriday tweets of 2018, from number 10 to 1.

What’s a ‘FossilFriday’? Every Friday, people post pics of their favorite fossils using the hashtag #FossilFriday, mainly on Twitter. This can be about famous specimens, odd fossils, museum collections, rare photos, scientific papers or blog posts. I love to join it & tweet about hominin fossils. Now, let’s go!

10. Unusual picture of a very iconic fossil, ER 1813 Homo habilis:

9. New studies on old fossils. Did Cro-Magnon 1 have neurofibromatosis type 1? 

8. This gorgeous hand of Australopithecus sediba

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The Top 10 hominin #FossilFriday tweets of 2017

This is the 4th one of a little tradition, my special Paleoanthropology annual report… The list of my favorite hominin #FossilFriday tweets in 2017, from number 10 to 1.

What’s a ‘FossilFriday’? Every Friday on Twitter, people share pics of their favorite fossils, related scientific papers or blog posts, by using the hashtag #FossilFriday. This is a great manner to show famous or rare pieces of museum collections, and to share research works. Every Friday I love to join & tweet about a different hominin fossil. Now, let’s go!

10. Very nice National Geographic hologram cover from November 1985, starring the Taung child:

Hominin #FossilFriday

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Bringing hominin fossils back to life: interview with paleoartist John Bavaro

Art and science. Paleoart is the scientific reconstruction of extinct life. Complementing the study of the fossil record, paleoart has become a major contribution of deep scientific knowledge combined with the author’s artistic insight. It was a great pleasure for me to meet John Bavaro, who has great knowledge and passion in the Human Evolution field. I hope you will enjoy this interview with John for Nutcracker Man, including several examples of his very up-to-date work…

Can you describe the process to reconstruct the appearance of hominins? In particular, how do you combine the fossil evidence together with other sources to provide them movement and life?

Paleoart John Bavaro. Turkana Boy

Paleoart by John Bavaro. Figure 1. Turkana Boy

I try to apply my own understanding to the anatomy to the model before I look at other artists so then I have a fresh perspective. But my niche is in digital art which I teach at Edinboro University of Pennsylvania.

I look at Kennis Brothers, John Gurche, Elisabeth Daynès, Viktor Deak, giants in the field who do reconstructions and I’m in awe.

We are a visual species. And I for one want to explore the possibilities. Perhaps that’s what sets us apart. Art follows science and vice versa. For instance, the Lucy skeleton or the Turkana boy skeleton totally “rewrote” history. In the case of Lucy we now know that she was hybrid tree climber AND a walker. In the case of Turkana Boy there’s clues about gait and the posture etc.  It’s a puzzle that constantly revealing itself. So art follows science in the tendency for equivocation and I’m not being insulting to science when I say that. In fact, every discovery that comes out now days “rewrites” the understanding of the “mythical textbooks”.  Now with the internet we’re getting more impatient. I for one, think that’s lazy clickbait. A teaser, hubristic or both If I read something that says that “new discovery which changes the way we look at things” I say, “Yeah, until the next time which is probably at this pace, a month away.” I know that science is continuingly changing, which is counter to the current understanding (in popular culture) of it which that it is static. Those in the field know about this, but modern society holds it up as basically like religion. “Well, Science says…….” But scientists know that it is ever-changing process. In this era, changes happen at dizzying pace that I can’t keep up with them quickly enough.  It’s like same way that T-Rex was pictured just 50 or 60 years ago with the tail down instead of up.

 

Your work is very up to date with all recent finds in human evolution. Let’s discuss three examples: Jebel Irhoud, Homo naledi and Denisovans.

Jebel Irhoud

You have created an illustration of the human from Jebel Irhoud, dated to 300 Ka and recently proposed as the earliest Homo sapiens known so far. However this has been contested because of the primitive traits of this specimens which are different from other skulls like Omo or Herto dated to 200 Ka. To what extend did you consider the Jebel Irhoud as ‘modern’ in your illustration?

Paleoart John Bavaro. Jebel Irhoud

Paleoart by John Bavaro. Figures 2, 3, 4, 5. Jebel Irhoud

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The supraorbital torus in hominin

The supraorbital torus (or brow ridge) is a very distinctive morphological trait in most of our hominin ancestors. What purpose does this feature serve? A few hypotheses around this topic are:

  • Dissipation of heavy chewing forces, produced by the jaw muscles and transmitted around the nose and the eye sockets.
  • Evolutionary result of the fulfilment of spatial demands between the orbits and the brain case.
  • Capacity to dynamically express affiliative prosocial emotions through highly mobile eyebrows.
  • Reinforcement of the frontal bone which was weaker in all the hominin species before Homo sapiens. This is a similar idea to explain the development of the chin in modern humans, as a reinforcement of a weaker jaw.
  • Protection of the skull and the eyes against blows.
  • A signaling effect, accentuating aggressive stares, thus its large size could have been sexually selected through generations. Is the lack of brow ridges related to self-domestication in modern humans?

However, many huge supraorbital tori are hollowed inside with large sinuses (for example: Petralona), suggesting that they did not bear or transmit physical forces from blows to the head or heavy chewing. Another iconic skull, Kabwe 1, has a much larger browridge than the minimum required to fulfil spatial demands, and its size has little impact on mechanical performance during biting.

I like the idea to think about a combination of several factors which made evolution work for a few million years. This post describes the supraorbital tori of 22 iconic hominins:

Australopitecines

Al 444-2: The largest Australopithecus afarensis skull yet discovered has an expansive supraorbital torus, thickened laterally and continuous superiorly-posteriorly with no interruption.

Sts 5 (Mrs. Ples) has a relatively small supraorbital torus, double arched in the front and projecting glabella. Another Au. africanus skull with many similarities is Sts 71, with a less broad torus in comparison to Sts 5, but with a similar expanded glabella.

Supraorbital torus Australopitecines

Supraorbital torus: Sts 5 (centre)-credit Wikipedia, AL 444-2 (left) and Sts 71 (right)-credit Roberto Sáez

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Quick summary of the new hominin footprints at Laetoli

Quick summary of the new hominin footprints at Laetoli

Background

  • Since the 1970s several prints and trails of mammal, bird and insect have been identified in 18 sites (labelled from A to R) out of 33 total palaeontological localities in the Laetoli area, Tanzania.
  • In 1978 a 27-meter footprint trail was found at Site G, with about 70 footprints corresponding to 3 hominins.  They were bipedal, had big toes in line with the rest of their foot, and their gait was «heel-strike» followed by «toe-off», that is, the same way modern humans walk.
  • The footprints were ascribed to Australopithecus afarensis, as suggested by the dating (3.66 Ma) and the fossils found nearby in the same sediment layer.

The new find

  • Site S is located only 150 m away from Site G. In October 2014 some excavation works were executed to assess the impact of building a museum including a protective covering for the Site G tracks. This yielded 14 hominin tracks plus other 529 tracks left by other animals including bovids, equids, girafs, rhinos…
Laetoli footprints

Figure 7 from Masao et al. 2016. Original caption: Southern part of the hominin trackway in test-pit L8. Footprints L8/S1-1, L8/S1-2, L8/S1-3 and L8/S1-4 are visible from left to right. The heel drag mark is well visible posteriorly to L8/S1-3.

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