With morphology, genetics & SDMs, we show that only 9 of the 20 described European Buthus species are valid! Descriptions based solely on morphology are prone to mistakes for these scorpions. Fantastic work led by Javi which I am honored to be part of it.
digitallibrary.amnh.org/items/c3e980...

This may suggest a trade off between grasping and holding with profound consequences of predatory strategies, diet and even venom evolution.

Thanks to @anthony-herrel.bsky.social and Arie van der Meinden for your supervision! It

If anyone needs a copy of the manuscript just drop me a message

Finally, we modelled the closing force per degree of rotation. Long-fingered species have a peak in closing force at the beginning of the closing event followed by a drop in force towards the end. The short-fingered species have their peak force toward the end of the closing

This muscle in both species have parallel long fibers with short sarcomeres, i.e., fast muscle contraction! However, in the fast species this muscle is big and with a relatively long moment arm. Good for torque production! This suggests a dual function depending on the contraction necessities.

Another main difference between the two chelae is in the size of the patellar muscle. In the long-fingered species it is almost 50% of the volume of all closing muscles while in the short-fingered species the volume of this muscle is only 1.4% of the whole chela closing muscles, almost vestigial!!

The super strong chela closing in short-fingered chelae is due to larger mechanical advantage (MA), long sarcomeres and stronger muscles with long moment arms. While the super fast closing in long-fingered chelae is due to low MA, short sarcomeres and stronger muscles with short moment arms

My official baptism of Bluesky!

Hot off the press!
My last chapter of PhD has been finally published! Here we compare the internal anatomy of the chela closing muscles in two species of scorpions at the extremes of the chela morphological gradient.

onlinelibrary.wiley.com/doi/10.1002/...