The tree frixel has undergone one of the more radical shifts in body plan in the Amphiterran timeline, with little to compare it to in ours. Alternately known as the ‘yoga frog’, the frixel engages in habitual bipedalism, but not in the way we would predict in our timeline. Instead, the front limbs have become the main support structures for bipedalism, the sternum acting as a sort of pelvis, and the hind limbs rotating up and out. The dentition has evolved for an omnivorous diet, with a clipping beak evolving at the front of the skull in order to consume both meat and plant matter.
The frixel may seem implausibly awkward, but, like a pterosaur on land, it’s not until the creature is in its element that it all comes together. The hind limbs are perfectly positioned to brachiate like our timeline’s gibbons, with long fingers and newly developed thumbs providing a perfect pivot for incredible tumbling acrobatics.
Like our primates, the mental requirements needed for complex three dimensional travel through the trees brings with it a rise in general cognitive ability. The braincase of the creature is relatively large, and frixels have been observed using tools and engaging in complex social activities. The scale of their intelligence is unknown, while it’s tempting to compare them to our timeline’s chimpanzees, amphibian intelligence is too foreign, too alien to project our anthropocentric tendencies upon.