Witnessing an Ancient Lineage of Cave Spiders

February 8, 2018

In Tasmania a main focus of our study was examining deep-time historical events and how they effect the biogeography of the land today. Throughout our time traveling from beaches on Maria island to forests in Maydena we had the privilege to physically look at how the historical events lead to the species and environments that were surrounding us.

One significant deep-time historical event that we studied is Gondwana. This is when all the Southern continents were joined 150 million years ago. We can then trace the dispersal species and their evolution to better understand these historical deep time events.

One of the plant species that we were lectured about and spotted out in person was Northofagus. Northofagus is a genus of 43 species. We can trace Gondwanan Northofagus  to present times and, according to one of our lecturers, is found in Australia, Hawaii, and a small island near Madagascar.

On our last day in Maydena we were lead through the bush with two field scientists. They helped us take our understandings of biogeography on a larger scale and focus it to patterns in Tasmania. We examined two more species of Gondwanan descent on our hike; an ancient shrimp that Alex caught as well as ancient cave spiders.

The cave spiders are especially relevant because we watched a documentary called Sixteen Legs which dives into the elusive Tasmanian cave spider and its sex life. We then got to go to the caves in Mt. Field National park and actually see these spiders! We were even able to see a cave spider guarding its egg sac. This is even more of incredible feat because it takes a long time for a cave spider to mate, and then lay, the eggs in their spider sacs.

Overall, these experiences we have are helping us see the puzzle pieces of evolution that form into the plants, animals, and environments that we see today.

Below is a series of pictures from the day. Picture Credits of the spiders in the cover photo and below to Anna!