Final answer:
Australopithecus anamensis, an early species of australopiths, showed evolutionary trends towards smaller dentition and prognathic jaws. Though specifics are less clear than for its relative A. afarensis, it lived around 4.2 million years ago in a likely woodland and grassland mixed environment.
Step-by-step explanation:
Australopithecus anamensis is a species of the australopiths that lived around 4.2 million years ago. This species showed a trend in human evolution through features such as the reduction in size of the dentition and jaw. While more is known about its successor, Australopithecus afarensis, anamensis as an earlier form would have exhibited some of these characteristics. One of the most complete australopith fossils is that of an A. afarensis individual known as "Lucy," which provided significant insights into the body structure and lifestyle of these early hominins. They possessed smaller canines and molars compared to apes, larger than those of modern humans, and had prognathic jaws.
The environment A. anamensis lived in was likely a mix of woodland and grassland, indicating a transition from a life in the trees to one that involved more time on the ground. However, the specifics regarding the environment of A. anamensis are less clear compared to its more well-studied relative A. afarensis.