Glad to have participate in such amazing project!
Javi, we have to repeat something similar very soon!

Finally, taking mito-nuclear discordance, hybridization patterns, morphology and species diatribution modelling we concluded that the most conservative hypothesis is that in Europe, only 9 species are sure to be valid.

During climate shifts over millions of years, species expanded and contracted their ranges. Isolated populations evolved separately into new species, but when ranges overlapped again, they could still interbreed, creating hybrids with traits between both parents.

We look more carefully and in few cases we found that some old species (e.g., B. pedrosousai and B. baeticus) were hybrid species.

Mithocondrial was kind of supporting a high number of clades while nuclear markers where reducing significantly the species within each cluster. Interestingly, some relationships between sister taxa were completely altered when comparing the two types of markers

One of the main problem in Eyropean Buthus os their extreme morphological variability. When we analyzed mithocondrial and nuclear markers we found that these two parts of the genoma were telling different story. The so called mito-nuclear discordance.

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