I was just briefly on this project in the very beginning of the project at Dneg. I was helping sculpting team, CG and VFX supervisor to explore some creature design ideas. However as it was really an early stage nothing actually stayed in the final film. Apart from bits and pieces on earlier Calvin's evolution stages.
Check an interview with our VFX supe Huw Evans - http://www.artofvfx.com/life-huw-evans-vfx-supervisor-double-negative/