Let me say this at the outset: I don’t expect the latest discovery of a “transitional fossil”—the kind of thing that was once called a missing link—to change anyone’s mind about evolution. I have gotten too many letters and emails from creationists and intelligent-design proponents to have any illusions that something as silly as, you know, data will persuade them that living things change through time as a result of random mutation and natural selection. (My favorite contained a sponge with a verse from the bible printed on it; the letter writer promised to pray for my immortal, if misguided, soul.)

With that preamble, it’s still worth noting what scientists are reporting in the journal Nature, for it’s a transitional fossil between transitional fossils. That is, the fish-like thing whose 365-year-old fossil was discovered by Per Ahlberg of Uppsala University in Sweden and colleagues in Latvia seems to lie half-way between the lobe-finned fish Tiktaalik (itself a transitional fossil between true fish and four-legged land animals) and primitive tetrapods such as Acanthostega and Ichthyostega.

The new fossil, of Ventastega curonica, is remarkably well preserved, allowing the scientists to scrutinize it from skull to pelvis. Its lower jaw resembles a tetrapod’s, while its fangs are more fish-like.

There was a time when those who rejected evolution asked where the transitional fossils were, but as more and more are discovered they’ve changed their tune (if my mail is any indication). According to one, he won’t believe in evolution until there are “billions” of transitional fossils. We’ll get back to you on that.