Paleolithic religions are a set of spiritual beliefs and practices that may have appeared during the Paleolithic time period. Paleoanthropologists Andre Leroi-Gourhan and Annette Michelson believe unmistakably religious behaviour emerged by the Upper Paleolithic, before 30,000 years ago at the latest, but behavioral patterns such as burial rites that one might characterize as religious — or as ancestral to religious behaviour — reach back into the Middle Paleolithic, as early as 300,000 years ago, coinciding with the first appearance of Homo neanderthalensis and possibly Homo naledi. Religious behavior is one of the hallmarks of behavioral modernity. There are several theories as to the moment this suite of behavioral characteristics fully coalesced. One theory links the germination of behavioral innovations to a cultural revolution among the early modern humans, which coincided with their arrival to Europe 40,000 years ago. A variant of this model sees behavioral modernity as occurring gradually, beginning with the Middle Stone Age. According to a third theory, characteristics that define behavioral modernity are not unique to the Homo sapiens, but arose over a long period of time, among different human types, including Neanderthals. Lower Paleolithic Religion prior to the Upper Paleolithic is speculative, and the Lower Paleolithic in particular has no clear evidence of religious practice. Not even the loosest evidence for ritual exists prior to 500,000 years before the present, though archaeologist Gregory J. Wightman notes the limits of the archaeological record means their practice cannot be thoroughly ruled out. The early hominins of the Lower Paleolithican era well before the emergence of H. s. sapiensslowly gained, as they began to collaborate and work in groups, the ability to control and mediate their emotional responses. Their rudimentary sense of collaborative identity laid the groundwork for the later social aspects of religion. Australopithecus, the first hominins, were a pre-religious people. Though twentieth-century historian of religion Mircea Eliade felt that even this earliest branch on the human evolutionary line "had a certain spiritual awareness", the twenty-first century's understanding of Australopithecene cognition does not permit the level of abstraction necessary for spiritual experience. For all that the hominins of the Lower Paleolithic are read as incapable of spirituality, some writers read the traces of their behaviour such as to permit an understanding of ritual, even as early as Australopithecus. Durham University professor of archaeology Paul Pettitt reads the AL 333 fossils, a group of Australopithecus afarensis found together near