Hello and welcome to 7 Days of Science.
7 Days of Sci-
Starting off the news this week, a study published in the journal Planetary Science Journal has
concluded that it may be possible to detect life on the moon Enceladus without landing
on it.
Enceladus is the sixth largest moon of Saturn, and considered one of the most likely bodies
in the solar system to hold life other than Earth.
NASA’s Cassini spacecraft discovered a large ocean under the surface of Enceladus, containing
materials that could well support the beginning of life.
It has been suggested that other activity on Enceladus could be indicative of it holding
life.
The idea that an orbiting spacecraft could work out whether or not there is life on Enceladus
is based on the idea that biological material could be ejected through vents in Enceladus’
surface, along with other material, like methane, that already is.
The team calculated models of Enceladus with different levels of cellular life and if an
abundance of cells would or would not be ejected to a suitable distance, finding that, even
with a space biosphere, instruments on an orbiting spacecraft could detect enough evidence
for life.
A fascinating study looking forward at, perhaps, an even more fascinating and exciting future,
albeit a fairly distant one.
Also in the news this week is a fascinating paper describing a new specimen of prehistoric
sea turtle that preserves some very interesting anatomy.
It’s a partial specimen from the Eocene of Denmark, but the material that’s actually
preserved is quite exceptional.
It likely belongs to the genus Eochelone, a widely-distributed Pan-Cheloniidae hard-shelled
sea turtle that lived at this time, and preserves quite a lot of soft-tissue remains including
scutes and a complete flipper outline.
Interestingly, though, the flipper seems to have been entirely scaleless and actually
had wrinkly skin, unlike the condition seen in modern Cheloniidae sea turtles which retain
scales across the body, and more like the modern Leatherback sea turtle which has reduced
scalation but is not a Cheloniid.
In the fossil specimen, these scaleless limbs were then combined with a bony carapace that
still had scutes across it, indicating a more complex evolution of these sea turtles than
had previously been appreciated, evolving an interesting mosaic of features as these
animals adapted to life in the oceans.
A really interesting discovery there then.
Finally for this week, there’s been an incredibly remarkable paper describing a new kind of
prehistoric bird.
Named Cratonavis zhui, it comes from the Early Cretaceous of China and the fossil of this
animal is absolutely beautiful.
Importantly, this bird is a member of a group known as the non-ornithothoracine pygostylians,
and actually sits in an intermediate position within the family tree, meaning it’s a key
species to study in order to understand bird evolution.
The combination of both bird-like and non-bird dinosaur-like features in this fossil is very
intriguing, with a skull that looks like a more basal - or primitive - dinosaur, while
the body is very bird-like.
Again, this shows how the evolution of these animals was very mosaic, with different feature
evolving at different stages.
It also looks as though Cratonavis was a raptorial predator, based on the morphology of its foot,
and overall it’s a really fascinating and important new find.
And that’s it for this week’s 7 Days of Science, I do hope you enjoyed, and we’ll
see you next Sunday