The Monkey Puzzle Puzzle

I work at Bristol Zoo's DinoZoo2 as Lead Dino Ranger. I love my job. It requires me to be happy and enthusiastic about prehistory on a daily basis, which is pretty much my general state of being anyway, so it doesn't require a huge amount of effort.

One of my roles is to provide talks and information about the different prehistoric creatures and fossils that we've got at the zoo at the moment. I've recently expanded my remit to include some of the prehistoric plants or Living Fossils that we have on site.

The one I've focused most time and energy on was the one that started it all for me: the Monkey Puzzle tree.

Last year, for DinoZoo, I led evening tours around the zoo, talking about each dinosaur in turn. I'd always stop at the Monkey Puzzle and talk about that. Somewhere in the dim recesses of my mind, I'd stowed the idea that the Monkey Puzzle was around at the time of the dinosaurs, and that its impressive armour was the result of evolutionary pressure to protect itself from browsing dinosaurs.

This year I double checked the fact. I found it almost impossible to track down any information about how old the Arucaria genus (the genus to which Monkey Puzzle belongs) actually is. Various sites attest to its great age, but none gave a definitive age or evidence for it. I was beginning to think I'd gone mad.

This Daily Mail article states that Monkey Puzzle fossils are known from the Mesozoic, but as this is from the  Permo-Triassic boundary (250mya) to the start of the Caenozoic (66mya), and spans the entire age of the dinosaurs, it wasn't a huge amount of help to me.

What I did find, however, was information about Arucaria mirabilis - it's not hugely closely related to the Monkey Puzzle, though it is in the same genus (it is more closely related to an Australian evergreen called a Bunya Pine). Its fossils date back to the right time: the Jurassic. Its cones are broadly similar to those of the Monkey Puzzle tree. It is, at least, a start.

More on other ancient plants later in the week, I hope - if you know anything else about the age of the Monkey Puzzle, let me know!