Abstract
The Zagros region and its hilly flanks, particularly its central parts in the provinces such as Kermanshah, Lorestan and Ilam have provided most evidences related to the Neolithic period and the transition from hunting and gathering to farming and herding. However, our understanding of the Neolithization process in the southern part of the Zagros mountains remains limited and poorly understood to this day. The excavation of Tap-e Bibizolaikhaei is the first Neolithic excavated site in the Kohgilouyeh region, providing new archaeological data. The primary objective of our research was to explore various aspects of the Neolithic way of life at the site, including recovering animal and plant remains to reconstruct economic practices and ancient ecology in the early Holocene period. Another important aim was to obtain samples for C14 dating to establish a reliable chronology for the site. To address these goals, we sought answers to significant research questions include: is the settlement of Bibizolikhaei exclusively a pre-pottery Neolithic settlement? What is the type of the settlement and how long did it last?? To what extent was the economic practices of Bibizolaikhaei people based on hunting and gathering and how much was it based on farming and herding? Based on the stone tools assemblage and the absence of contemporaneous pottery, we infer that the site belongs to the pre- pottery Neolithic period. Regarding the ecological features of the site, we documented that the subsistence practices of its settlers involved a combination of gathering plant seeds and wild grains, as well as hunting small mammals and engaging in small-scale fishing. This article employs a descriptive-analytical research method wherein we describe and analyze the excavated findings within their context. Additionally, the C14 results confirm that the site was occupied during the first half of 8th millennium BC.  
Keywords: Tap-e Bibizolaikhaei, Pre-Pottery Neolithic, Neolithization, Kohgilouyeh.

Introduction
In the Iranian plateau, the most important evidence regarding transition from hunting and gathering to farming and herding comes from the Central Zagros and its hilly flanks, i.e.in the regions such as Kermanshah, Lorestan and Ilam provinces (e.g. Braidwood et al., 1961; Smith 1976; 1990; Mortensen, 1972; Meldegaard et al., 1963; Matthews et al., 2013; Riehl et al., 2015; Darabi et al., 2011). Our understanding of the Neolithic period in the southwestern parts of the Zagros region has been significantly enhanced through excavations at various sites, including of Ali Kosh (Hole et al., 1969), Choghsefied (Hole, 1977) and Chogha Bonout (Alizadeh, 2003). Except for few sites with possible finding from this period, excavations at Seyedeh Khtoun Cave in Arsanjan (Tsuneki and Mirzaye, 2012) and joint Iranian/Japanese project in framework of Tang-e Bolaghi recue excavations, have reveled evidence of this period in the southern Zagros. Moreover, excavations at Tap-e Rahmatabad (Azizi et al., 2014), Ghasre Ahmad (Kamjan et al., 2018) and Tol-e Sangi (Alizadeh, 2021: 4) are recent research in the region. Several reported sites from Chehar Mohal and Bakhtyari (Zagarell, 1982; Daujat et al., 2016) including Ghale Rostam provide information about this period. In addition to sites of other periods, archaeological survey of the Kohgilouyeh region led to identification of a number of Neolithic period sites that shows the importance of the region for the studies on the Neolithic. The primary objective of our research was to explore various aspects of the Neolithic way of life at the site, including recovering animal and plant remains to reconstruct economic practices and ancient ecology in the early Holocene period. Another important aim was to obtain samples for C14 dating to establish a reliable chronology for the site. To address these goals, we sought answers to significant research questions include: is the settlement of Bibizolikhaei exclusively a pre-pottery Neolithic settlement? What is the type of the settlement and how long did it last? To what extent was the economic practices of Bibizolaikhaei people based on hunting and gathering and how much was it based on farming and herding? Based on the stone tools assemblage and the absence of contemporaneous pottery, we infer that the site belongs to the pre- pottery Neolithic period. Regarding the ecological features of the site, we documented that the subsistence practices of its settlers involved a combination of gathering plant seeds and wild grains, as well as hunting small mammals and engaging in small-scale fishing. This article employs a descriptive-analytical research method wherein we describe and analyze the excavated findings within their context. Additionally, the C14 results confirm that the site was occupied during the first half of 8th millennium BC. Considering the geological landscape features of the region and its ecological potentials, it is plausible to hypothesize that the occupation of the site at Tap-e Bibizolaikhaei may have been seasonal in nature. 

Discussion
The excavation of Bibizolaikhaei revealed three layers and a number of features. Although we could not reach to the virgin soil, remains of pebble floor, stone oven, a possible wall, animal and botanical remains and lithics were the important finds of our excavation. Among them, remains of a pebble floor is the most significant. Apparently, the use of pebble floors was common in the mountainous landscape of Zagros during the Neolithic period (e.g., Darabi et al., 2011: 256; Braidwood et al., 1983: fig 66). Lithics recovered from the excavation are based on production of bladelets which are the same Zagros Mlefatian tradition. All deposits were floated, however, there is no clear evidence of domesticated plants; this might be due to the revealed space and small scale of the excavation. However, the presence of stone mortars, pestles, grinding slabs and pounders that were recovered during the excavation and on the surface of the site shows that processing of plant seeds had an important role for the subsistence of the settlers of the site. Remains of animal bones such as domesticated goats and wild sheep indicates the presence of these animals in the diet of the settlers of the site. Due to the absence of Neolithic pottery in the excavation and on surface of the site, it is possible to infer that the site belongs to the pre- pottery Neolithic period. According to the results of C14 samples, it is certain that the site has been inhabited during the first half of the 8th millennium BC. For environmental reasons, Kohgilouyeh was the region where, until two decades ago, a significant portion of its residents relied on a semi-sedentary lifestyle. Therefore, until further studies are conducted, we can presume that this subsistence strategy has a longstanding history and should be taken into account when considering the Neolithic settlers of Bibizolaikhaei.

Conclusion 
Bibizolaikhaei is a pre-pottery Neolithic site and representative of the Neolithic sites of the Kohgilouyeh region. The C14 results indicate that the site was inhabited at least since the first half of 8th millennium BC. Considering the importance of the Neolithic period in the evolution process of the human societies, the need of continuing research at Bibizolaikhaei to find out various aspects of probably the oldest settlement of this part of Zagros appear obvious. By continuing investigations at this site, we expect to be able to understand the evolutionary trajectories of this part of Zagros is relation to the other parts of this mountainous range. 
Now with increased awareness from central Zagros (i.e. the site of Shaikhiabad), southern Zagros (including the sites of Tange Bolaghi and Rahmatabad) and western borders of the Zagros (i.e. the site of Choghagolan), it is necessary to explore and understand the Neolithic societies and human adaptations that existed in the regions such as Kohgilouyeh with its diverse landscape during the Holocene period. Bibizolaikhaei provides relevant information regarding this less understood region.