First-ever video shows a tarantula eating an opossum

God, I hate spiders.


I’m not generally arachnaphobic, but that was definitely creepy. Thanks for sharing that, I think…


That was awesome. I used to work on mygalomorph spiders. They’re so cool.


Why do you like them? Aren’t they just big spiders? Are they a single clade or are their several?

They’re a single clade. Not nearly as diverse as araneomorph spiders (the other major clade), and they’re not always big, though frequently they are.

I spent a lot of time as an undergrad and M.S. student collecting trapdoor spiders all over California. Instead of building webs to catch prey, they dig these beautiful burrows that they line with sick (sometimes 6-8 inches deep).

Some species then build these doors at the end of the burrow, and cover them with thin filaments of silk. They then wait behind the door, and when a prey animal (insects, other spiders, etc.) walks over the door, they can feel the tension in the silk line, and then the pop out to grab their prey.

They’re a serious pain to collect, but they’re docile (mostly - there are some species that are more aggressive), and I just developed a real appreciation for them.


What types of research questions would you ask? Help educate us about the science done by spider collector scientists?

What types of research questions would you ask? Help educate us about the science done by spider collector scientists?

The lab I was working in was an arachnid phylogenetics lab. We mostly focused on questions regarding:

  • lineage diversity and phylogenetic relationships across arachnids (both at small and large scales)
  • challenges regarding how to delimit species when morphology is highly conserved but genetic differences are much more stark (as is often the case among mygalomorphs)
  • California phylogeography and historical biogeography
  • Applied genetics to conservation questions

Incidentally, my PI at the time, Marshal Hedin, is a WUSTL alumn!


What are the sorts of things your group discovered? What were some of the coolest papers?

A couple things come to mind:

  • We discovered that cryptic species diversity is probably very widespread among a variety of sedentary arachnid groups, but disentangling bona fide speciation from population genetic structure is challenging.
  • Some of my colleagues used phylogenetic relationships to examine historical patterns of spider biodiversity across the California landscape and found some evidence of large scale dispersals.
  • During my master’s work (which was kinda of just an excuse for me to learn how to do bioinformatics with high throughput sequencing data) I looked for taxonomically restricted genes from transcriptomic data and found some provisional evidence that some of them may be under positive selection, although relaxed selection was probably more common.

Here are some of the more interesting papers that came out of that lab while I was there (though I was not directly involved in all of this work):

Hedin M, D Carlson & F Coyle. 2015. Sky island diversification meets the multispecies coalescent – divergence in the spruce-fir moss spider ( Microhexura montivaga, Araneae, Mygalomorphae) on the highest peaks of southern Appalachia. Molecular Ecology 24, 3467–3484.

Hedin M. 2015. High stakes species delimitation in eyeless cave spiders ( Cicurina , Dictynidae, Araneae) from central Texas. Molecular Ecology 24, 346-361.

Satler JD, BC Carstens & M Hedin. 2013. Multilocus species delimitation in a complex of morphologically conserved trapdoor spiders (Mygalomorphae, Antrodiaetidae, Aliatypus ). Systematic Biology, 62, 805–823.

Hedin M, J Starrett & C Hayashi. 2013. Crossing the uncrossable: Novel trans-valley biogeographic patterns revealed in the genetic history of low dispersal mygalomorph spiders (Antrodiaetidae, Antrodiaetus ) from California. Molecular Ecology 22, 508-526.

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