What does Engels mean by "tree-climbing ape"?

The apes who climb trees refer to the ancient apes who live in trees. According to the existing data, the tree-climbing apes generally refer to three kinds of apes: (1) primitive apes: this is the earliest known ancient ape, which was discovered in Fayon, Egypt, about191years ago, and lived about 30 million years ago. They can jump flexibly from tree to tree. (2) Egyptian ape-man: It was also found in Fayong, Egypt, and lived about 28-26 million years ago. They also had 32 teeth, and the arrangement order was similar to that of modern ape-man and human teeth. (3) Forest ape:/kloc-0 was first discovered in France in 856, and later similar fossils were found in Europe, Asia and Africa. They lived about 230-654.38 million years ago. Like primitive apes, they are forest animals, crawling on all fours and climbing by arms. Many anthropologists believe that the above three kinds of apes may be the common ancestors of human beings and modern apes.

Correction: Engel's article "The Role of Labor in the Transformation from Ape to Man"