Kazakh phoenix rises from the bone fragments

A recently published journal article announced the discovery of Samrukia nessovi, a giant bird from prehistoric Kazakhstan (Naish D, Dyke G, Cau A, Escuillié F & Godefroit P 2011, “A gigantic bird from the Upper Cretaceous of Central Asia”, Biology Letters doi: 10.1098/rsbl.2011.0683).

Samrukia – named after the Samruk, a pheonix-like bird from Kazakh mythology – could have been 2-3 m tall, or had a 4 m wingspan, depending on whether or not it could fly. And it lived in the late Cretaceous period, over 65 million years ago.

What’s incredible is that all of this was deduced from a pair of fossilised jaw bones dug up decades ago and, until now, languishing unidentified in Belgium.

How can palaeontologists reach such incredible conclusions from mere bone fragments?

What the Samrukia may have looked like if it either could or couldn't fly (left and right, respectively), compared for size with a human and a typical bird from the same period. (Image by John Conway)

To find out, I recommend popping over to the rather excellent blog Tetrapod Zoology, written by Darren Naish, who also happens to be one of Samrukia‘s discoverers (as well as an expert on many other aspects of zoology and palaeontology, including the science of Godzilla).

The discovery, or rather identification of Samrukia is a fascinating tale of scientific deduction that demonstrates how bones from different types of creatures have distinct properties that help you to tell them apart and, importantly, rule out other possibilities.

I’ll leave the rest of the story to Dr Naish; but before you go there, it might help to know the following technical terms:

• Ramus, plural rami, is the section of lower jaw that extends from the joint with the skull. You have one on each side of your head.
• Symphyseal region, or simply symphysis, is the part where the two rami meet. You may know this as your chin.
• Cotyles and pneumatic foramina (singular foramen) are features of rami from up where they join the skull.
• Theropods are from the suborder Theropoda, which includes certain two-legged dinosaurs as well as modern birds.

Find out the rest at Tetrapod Zoology…

Russian dolls of the bacterial world

Mealybugs are scale insects that feed on plant juices. And like other animals, including us, they have bacteria living inside them.

One of these species of bacteria, Tremblaya princeps, recently had its genome sequenced, leading to a remarkable discovery. It turns out to have a symbiotic relationship with another species of bacteria, Moranella endobia, that lives inside it, like microscopic matryoshkas.

A female mealybug, Planococcus citri; its head is to the left (image by Christian Fischer, via Wikimedia Commons)

Their relationship is so symbiotic, that is, they depend on each other so much, that it seems Tremblaya has lost a lot of its genes. In fact, with only 139,000 bases, it has the smallest genome ever seen in a cell.

Perhaps the phenomenon is best described using the medium of poetry:

Big fleas have little fleas,
Upon their backs to bite ‘em,
And little fleas have lesser fleas,
and so, ad infinitum.

Except in this case, of course, the bitin’ seems to help.

Reference (the science, not the nursery rhyme): McCutcheon JP & von Dohlen CD 2011, “An interdependent metabolic patchwork in the nested symbiosis of mealybugs”, Current Biology, vol. 21, no. 16, pp. 1366-1372, doi:10.1016/j.cub.2011.06.051

Domestic life of silver foxes

Anyone who has a cuddly, friendly dog at home has to have wondered at some stage how they could ever have descended from vicious wild wolves.

Well, one of the world’s longest running experiments has been trying to find out by duplicating the process with the previously untamed, but dog-like, silver fox (note: by “silver fox” we don’t mean your Shaun Micallef or George Clooney – by all accounts they’re already housebroken).

Over 50 years, experimenters from the Institute of Cytology and Genetics at Novosibirsk, currently led by Lyudmila Trut, have been selecting for foxes that are less afraid of humans. The descendants that result have turned out to be very similar to domestic dogs, in behaviour but also in features like floppy ears and wagging tails.

Find out more from the study’s collaborators at Cornell University, or watch the following excerpt from the BBC Horizon program, The Secret Life of the Dog: