Todd Wood's Take on Danuvius

Todd Wood is always interesting to read, even if I don't share his chronological leanings.  He has thoughts on the new Miocene ape from Bavaria, Danuvius:

Based on the fragmentary remains, we make some really interesting observations about the anatomy of Danuvius. These apes had strongly opposed big toes, which would allow them to effectively grip things with their feet. Their tibiae (shinbones) have the kinds of joints that would allow them to walk upright, and their femora (thighbones) support that conclusion. These apes might have been in some way bipedal. The arm bones they found have traits that are associated with suspensory locomotion, like hanging from tree branches. The body size was fairly small, about the mass of a bonobo.

As I mentioned in my post, I think the evidence for bipedalism is vastly over-stated and, even if it can be shown that this “Extended Limb Clambering” is shared by other fossil ape finds from the region, there is no particular reason to think that these critters were ancestral to later hominins. It is entirely likely that they exhibited a separate adaptation to this particular style of locomotion.  Todd raises some other questions, though, that are not answered in the paper:

So why not address similarities of Danuvius to later fossil hominins? The authors are trying to establish a new means of locomotion that they call Extended Limb Clambering (ELC). So they compare Danuvius to living primates (where the authors know how they get around), and they're interested in comparing it to contemporary Miocene apes of Europe. But they're not all that excited about other comparisons to later fossil forms like Ardipithecus, Australopithecus, or Orrorin. They also don't relate their findings to later fossil apes in Europe like Graecopithecus or the Trachilos tracks, both of which have been linked to hominins or bipedality. Perhaps they don't think those things are worth talking about (maybe because they're skeptical of Graecopithecus like I am), but I guess I just don't agree.

I think that part of the reason that these questions are not raised is because there is so much of a gap between these finds, chronologically and geographically. There is simply with which to relate them. As Todd points out, the hominin status of Graecopithecus is dubious, at best, and, even if the Trachilos tracks are hominin, they are still quite a distance from Bavaria and six million years later in time.

For now, this fossil ape stands on its own.  If we find other evidence of incipient bipedality in other forms in the area and can relate them to later forms, then the picture might change.  For now, though, Danuvius is a very interesting, odd Miocene ape. 

New BioLogos Post on the Greek Footprints

My article on the Trachilos footprints has gone up at BioLogos.  As always, comments welcome both places. 

Greek Fossil Site Vandalized

Someone has vandalized the site containing the 5.7 million year old footprints in Crete.  Australian News Limited reports:

Some four to 10 prints appear to have been hacked out of the rock.

And graffiti has been sprayed over much of the remainder.

It’s an attack with devastating implications for the science of understanding humanity’s past.

“We are fortunate that many of the best tracks remain — the people who did it clearly didn’t know what they were looking for,” Professor Bennett writes. “Our guess is that they were simply intending to sell them.”

The site had been recognised under Greek heritage laws, and local authorities were supposed to be watching it.

Greek media reports a 55-year-old man has been arrested in western Crete and that many of the prints may have been recovered.

I certainly hope so. And I certainly hope that very hefty fines and possibly jail terms will be levied against those involved. As for the people in the organization that was supposed to be watching the site, I hope they are out of a job.

Time will have to tell how much damage was actually done but this is nothing less than a travesty.  Because truly stupid people are never in short supply, many of the Neandertal sites in Europe were also looted before they could be fully excavated.  This should be embarrassing to the Greek government. 

5.7 Million Year-Old Human Footprints Found on Greek Island of Crete

Great Googlymoogly!  This one is lighting up all over the Internet.  Fossil footprints have been found in the southern Greek Island of Crete, near the village of Trachilos, that appear to have the distinctive heel-toe-off gait of bipedal humans.  The catch? The prints are 5.7 million years old!  From PhysOrg:

Human feet have a very distinctive shape, different from all other land animals. The combination of a long sole, five short forward-pointing toes without claws, and a hallux ("big toe") that is larger than the other toes, is unique. The feet of our closest relatives, the great apes, look more like a human hand with a thumb-like hallux that sticks out to the side. The Laetoli footprints, thought to have been made by Australopithecus, are quite similar to those of modern humans except that the heel is narrower and the sole lacks a proper arch. By contrast, the 4.4 million year old Ardipithecus ramidus from Ethiopia, the oldest hominin known from reasonably complete fossils, has an ape-like foot. The researchers who described Ardipithecus argued that it is a direct ancestor of later hominins, implying that a human-like foot had not yet evolved at that time.

The new footprints, from Trachilos in western Crete, have an unmistakably human-like form. This is especially true of the toes. The big toe is similar to our own in shape, size and position; it is also associated with a distinct 'ball' on the sole, which is never present in apes. The sole of the foot is proportionately shorter than in the Laetoli prints, but it has the same general form. In short, the shape of the Trachilos prints indicates unambiguously that they belong to an early hominin, somewhat more primitive than the Laetoli trackmaker. They were made on a sandy seashore, possibly a small river delta, whereas the Laetoli tracks were made in volcanic ash.

And now, the other shoe.  How do we know how old the fossil footprints are?  

The coastal rocks at Trachilos, west of Kissamos Harbour in western Crete (Fig. 1a–c), lie within the Platanos Basin, and present a succession of shallow marine late Miocene carbonates and siliciclastics of the Roka Formation, a local development of the Vrysses Group (Freudenthal, 1969 ; van Hinsbergen and Meulenkamp, 2006; Figs. 1d, e and 3a, b). At the top, this marine succession terminates abruptly in the coarse-grained terrigenous sedimentary rocks of the Hellenikon Group (Figs. 1d and 3e, f), which formed by the desiccation of the Mediterranean Basin during the Messinian Salinity Crisis (van Hinsbergen and Meulenkamp, 2006), an event dated to approximately 5.6 Ma (Govers, 2009). The succession (Fig. 1d) contains an emergent horizon with well-preserved terrestrial trace fossils and microbially induced sedimentary structures (Fig. 3d) immediately overlying shallow water ripplemark structures (Fig. 3c).¹

So, the authors are a tad more circumspect than the writers of the PhysOrg story.  The authors posit two hypotheses for their results: 1. the tracks represent the gait of a basal hominin, which explains the non-divergence and shape of the big toe as well as the shape of the ends of the other toes, which resemble those of a human foot and not a non-human foot.  This fits approximately with the dates of the north African remains of Orrorin and, perhaps, that of Sahelanthropus (although that is pretty much a surface find).

The Messinian Crisis was a period of time during the Miocene epoch during which the Mediterranean Sea almost completely dried up.  This crisis began around 6 million years ago and ended around 5.3 million years ago with what is known as the Zanclean flood.  It is estimated that once the barrier at the Strait of Gibraltar was broken, the Mediterranean Sea refilled within two years, which means that the sea level rose at an estimated 30 feet per day.

Okay...now, lets go back here, to the story that came out about four months ago, establishing the possibility that the last common ancestor to apes and humans was in Europe.  In that study, a jaw with human root patterns and an isolated premolar that have both been attributed to Graecopithecus, were re-examined and found by the researchers to have hominin affinities, a surprising conclusion, given their age of 7.15 million years.  At the time that story appeared, I remarked that it was a bit of a stretch to hang one's hat on one premolar and partial ape-like mandible, but in the context of the new finds, maybe not so much.  This strengthens the (admittedly far-fetched) notion that our ancestors did, in fact, originate somewhere in southeast Mediterranean Europe and, over the course of the next two and half million years ago, migrated south to north Africa.

As Per Ahlberg was quoted as saying:

"This discovery challenges the established narrative of early human evolution head-on and is likely to generate a lot of debate. Whether the human origins research community will accept fossil footprints as conclusive evidence of the presence of hominins in the Miocene of Crete remains to be seen."

This is huge news.  Even if we can't place the LCA in southern Europe, we now have bipedalism extending back into the late Miocene. 


¹Gerard D. Gierliński et al, Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete?, Proceedings of the Geologists' Association (2017). DOI: 10.1016/j.pgeola.2017.07.006