Spinolestes xenarthrosus

Spinolestes xenarthrosus was a eutricodont foudn in the Las Hoyas Quarry in Cuenca, Spain, which dates to the Barremian age of the Cretaceous.

The holotype specimen (MCCMLH30000) of Spinolestes was found in remarkable condition, as a complete skeleton with its pinna (outer ear) fur, protospines, and dermal scutes preserved. Because the preservation of the integumentary structures are an important part of this discovery, I chose to portray the grooming and itching behaviors associated with having fur.

I took creative liberties in the lighter and varied body coloring of the animal, which would not plot with research into the preserved melanosomes of six Mesozoic mammaliaform fossils which found that the six fossils studied had “uniformly dark brown coloration with minor differences.” (Li et al., 2025).