"Australopithecus sediba Comfortably Walked on Two Legs, But Could Climb Like Ape" - see http://www.sci-news.com/othersciences/anthropology/australopithecus-sediba-locomotion-10301.html . The article says in the part the following.
"The discovery also shows that like humans, Australopithecus sediba had only five lumbar vertebrae."
'The authors concluded that Australopithecus sediba is a transitional form of ancient human relative and its spine is clearly intermediate in shape between those of modern humans (and Neanderthals) and great apes.
“Issa walked somewhat like a human, but could climb like an ape,” Professor Berger said.'
See also https://theconversation.com/fossil-spine-suggests-ancient-human-relative-walked-like-us-but-climbed-like-an-ape-172966 . The scientist who is the lead author of the science journal article article (at https://www.biorxiv.org/content/10.1101/2021.05.27.445933v1.abstract ) about the new fossil find for the species says the following.
"To approach A. sediba’s evolutionary relationship to other hominins, character-based analyses of the whole body are needed, and we’re getting more and more of A. sediba every year. Given what this and other research has shown, I think it’s a candidate for a close relative of the genus Homo. Hopefully Issa’s skull was not destroyed by miners: recovering that and other body parts from both her and Karabo will go a long way in resolving the debate."