Two exquisitely preserved neonate cave bear siblings from Equi Terme (Tuscany, Italy; Upper Pleistocene)

We report on two exquisitely preserved, extremely small Ursus spelaeus skeletons that were found in 2014 at the karst cavity known as "Tecchia di Equi", in the Apuan Alps (Massa-Carrara Province, Tuscany, central Italy). The most complete specimen includes the skull, which displays an undeformed three-dimensional morphology and is still connected to the cervical vertebrae. The cervical and thoracic vertebrae and the ribs are fully articulated. The 23 mm-long scapulae and the right humerus and tibia are also preserved. The second specimen displays a fairly complete rib cage, part of the vertebral column and the 26 mm-long right scapula. The preserved forelimbs include both the 31 mm-long humeri as well as the corresponding ulnae and radii. Overall, the two studied cubs stand out for their excellent preservation state. Many features of both skeletons reveal their overly young ontogenetic age, namely: the cranium is edentulous, and displays unfused sutures and open fontanelles; the vertebrae are only partly ossified; and the long bones lack the epiphyses. By comparing the measurements of the scapulae and long bones of the studied specimens with those of very young conspecific individuals from other sites of central Europe, an age at death of less than a week is proposed for both cubs, which most likely belong to the same litter. They may have died from starvation shortly after birth, similar to what happens to many modern bear cubs due to the often critical nutritional conditions of pregnant females during hibernation.