Archaeological research has mainly focused on stone tools, pottery, and metal tools excavated from ruins, while natural relics such as animal bones and plant seeds have been neglected due to the perception that they are not directly related to human activities. Recently, anatomical studies on animal bones discovered from ruins have helped us understand the eating habits and cultural levels of humans at the time. It can also identify the types and distribution patterns of animals that were hunted or raised at that time and even identify animal diseases [1-4].

Due to environmental characteristics such as climate and soil that do not easily retain organic matter, animal bone relics excavated from ruins on the Korean Peninsula have mainly been excavated from shell mounds [3,5], wetlands [6,7], and tombs [8,9]. They have also been excavated from ponds and wells [10]. Most studies on prehistoric animal remains found on the Korean Peninsula are about the livelihood economy using animal resources [11,12]. However, animal bones from the Three Kingdoms period have been mainly reported to be associated with animal sacrifice rituals as well as dietary life [13-15].

This study investigated Nyctereutes procyonoides bones identified among animal bones excavated from a well site in Gasan-ri, Ibanseong-myeon, Jinju, Korea. These bones are presumed to be from the Three Kingdoms period. This study examined the sizes and characteristics of N. procyonoides bones of the period through gross anatomy.

Animal bones were excavated from a well site in Gasan-ri, Ibanseong-myeon, Jinju [16]. These excavated N. procyonoides bones were classified by body part. For comparative measurement with existing animal bones, animal skeletal specimens stored in the anatomy specimen lab of the College of Veterinary Medicine, Gyeongsang National University were used to compare and analyze animal skeletal specimens that were similar to raccoon bone relics in terms of species and size.

Excavated animal bones were classified by body part according to the method of Schmid [17]. Skeletons were divided into skull, vertebrae, ribs, hip bones, bones of the forelimb, and bones of the hindlimb according to body part. N. procyonoides bone relics were measured using a Vernier Calipers (Mitutoyo, Japan) according to the method of Driesch [18].

Excavated animal bones were found in a well about 30 m east of the Three Kingdoms period site in Gasan-ri, Ibanseong-myeon, Jinju. Of the 447 identified animal bone relics, 59 (13.2%) were classified as belonging to 2 N. procyonoides (Table 1). The weight of N. procyonoides bones was 47.14 g, which was 4.83% of the total weight of identified animal bones (975.30 g) (Table 1). Skeletal measurements of identified N. procyonoides bones were compared with measurements of the skeleton of the extant raccoon (280 mm in height and 380 mm in length).

The total length of the maxilla of a N. procyonoides bone used as a standard for skull measurement was 83.16 mm and the greatest breadth of occipital condyles was 22.00 mm. Total length of the mandible was 67.97 mm and the angle process-infradentale was 66.91 mm. Physiological length of the body was 8.24 mm for the 4th cervical vertebra and 8.82 mm for the 1st cervical vertebra. The height along the spine of the scapula was 47.70 mm. For forelimbs, the height along the spine of the scapula was 47.70 mm, the greatest length of the humerus was 56.72 mm, the greatest lengths of the radius were 64.59 and 46.72 mm, the greatest length of the ulna was 57.76 mm. The greatest lengths of the pelvis were 8.00 mm and 51.69 mm. In the hindlimbs, the greatest lengths of the femur were 78.41 mm and 59.60 mm, the greatest length of the tibia was 81.70 mm, and the greatest lengths of the fibula were 77.19 mm and 56.52 mm.

The skull was preserved in 5 pieces, with many parts including the right parietal bone, occipital bone, and temporal bone damaged and lost (Fig. 1) [1]. Two mandibles (1 left, 1 right) were preserved. However, their coronoid processes were damaged (Fig. 1) [2,3].

Teeth were preserved in 4 pieces: third and 4th premolars on the right maxilla and 4th premolars on the left and right mandibles (Fig. 1) [1-3]. Judging from the eruption of the third and 4th premolars, this N. procyonoides was estimated to be 5 to 6 weeks old [19].

There were 9 vertebrae in total, 3 cervical vertebrae (Fig. 1) [4-6], including one axis (Fig. 1) [4]. There were 4 thoracic vertebrae (Fig. 1) [7-10], one lumbar vertebra (Fig. 1) [11], and one sacral vertebra (Fig. 1) [12]. Eleven ribs (6 left, 5 right) were identified (Fig. 2) [1-11].

Among bones of the forelimb, there were 2 scapulae (1 left, 1 right; Fig. 2) [12,13]. There were 2 humeri (1 left, 1 right). They were confirmed to belong to 2 different-sized individuals. The left humerus belonged to a smaller individual and the right humerus belonged to a larger individual (Fig. 2) [14,15]. There were 2 radii (1 left, 1 right; Fig. 2) [16,18] and 2 ulnas (1 left, 1 right; Fig. 2) [17,19]. There were 2 metacarpal bones, with proximal and distal ends slightly damaged (Fig. 2) [20,21].

Hip bones were confirmed to have 2 ilia (1 left, 1 right) and one ischium (0 left, 1 right), with the pubis was missing (Fig. 3) [1,2].

For bones of the hindlimb, there were 2 femurs (1 left, 1 right) from 2 different-sized animals (Fig. 3) [3,4]. There were 3 tibias (2 left, 1 right), but only one left tibia (1 left, 0 right) remained in the larger individual, and 2 (1 left, 1 right) remained in the smaller individual (Fig. 3) [6,9,10]. There were 4 fibulae (2 left, 2 right). In both individuals, proximal and distal ends of the left and right fibulas were slightly damaged (Fig. 3) [5,7,8,11]. Tarsal bones included one talus (0 left, 1 right) and one calcaneus (0 left, 1 right; Fig. 3) [12,13]. There were 8 metatarsal bones, with proximal and distal ends slightly damaged (Fig. 3) [14-21].

The N. procyonoides is a mammal belonging to the genus Raccoon in the family Canidae and is endemic to East Asia. It is distributed from the southern Russian Far East to China, Korea, northern Vietnam, and Japan, and has survived since prehistoric times [20,21].

Animal bone relics excavated from the well site of Gasan-ri, Jinju are generally estimated to be before the 8th century [16]. N. procyonoides bones accounted for 13.2% (weight ratio, 4.83%) of all animal bones excavated from the Gasan-ri site. In a study on Paleolithic animal bone relics on the Korean Peninsula, 5 N. procyonoides bones (7.5%) were found in the Hwacheon-dong cave site, 5 N. procyonoides bones (5.5%) in the Daehyeon-dong site in Yeokpo, Pyongyang, and 3 N. procyonoides bones (1.9%) in the Seungri-san site in Deokcheon, Pyeongnam-do, which accounted for a relatively small proportion of the excavated animal bones [1]. In the Dongsam-dong shell mound site in Busan, a representative example of the cultural aspect of the Neolithic age, terrestrial mammals were mainly deer and wild boars, while otters such as N. procyonoides, brown bears, and tigers were identified. N. procyonoides bones were excavated in small quantities [22]. Remains of terrestrial mammals excavated from the Yongwon shell mound in Jinhae estimated to be from the Bronze age of the 3rd to 4th century included wild animals such as deer, wild boars, roe deer, otters, and N. procyonoides, as well as domestic animals such as dogs and cows, although the proportion of N. procyonoides was very small [3]. A small number of N. procyonoides bones have been found in the Sugari shell mound in Gimhae. They have been estimated to be from the Three Kingdoms period [5]. Meanwhile, it is known that N. procyonoides used by humans on the Korean Peninsula since prehistoric times are very similar to species of raccoon dog currently inhabiting the Korean Peninsula [21].

Animal remains excavated from the well site in Gasan-ri, Ibanseong-myeon, Jinju are believed to be relics from the Three Kingdoms period. Of them, 6 species of animals, including a N. procyonoides, wild boar, deer, frog, and sparrow, have been identified [16]. Animal species excavated from relics on the Korean Peninsula can be largely divided into wild animals and domestic animals. Wild animals used by humans since prehistoric times include deer, wild boar, sea lion, fox, roe deer, whale, weasel, and badgers, and domestic animals include cows, dogs, and horses [1,2]. However, the ratio of use varied by relic, with medium-sized wild animals such as deer and wild boar having the highest ratio, while N. procyonoides animals were used in small quantities, suggesting that they were used additionally [6-9,23-25]. These differences in animal use patterns are presumed to be related to hunting wild animals or raising livestock according to the local environment. They are presumed to be deeply related to the way of using animals by people at the time.

Regarding the utilization of animal remains discovered on the Korean Peninsula, animal sacrifice rituals have attracted attention due to the analysis report on various animal remains excavated from the Imdang site in Gyeongsan [8,9]. Animal archaeologists understand that if a complete individual has been buried in the site, it might have been buried due to sacrifice and that if head, internal organs, and feet are removed, it might have been buried as food [26]. In addition, people of the Three Kingdoms period recognized that wells were sacred spaces where dragons lived. Whenever they faced natural difficulties, they threw animals into ponds or wells as a trace of ritual acts to achieve human goals through the offering of sacrifices [10]. The skull of a 5 to 6 weeks old N. procyonoides excavated from a well site in Gasan-ri, Ibanseong-myeon, Jinju had a fractured part of the parietal bone from the crown point where the frontal bone and parietal bone were located along the midline toward the occipital bone. It could be assumed that the fracture of the N. procyonoides skull by artificial impact was made to utilize the brain. N. procyonoides bones were also excavated as a full-body skeleton including the skull, vertebrae, ribs, humerus, ulna, femur, tibia, and fibula. It could be assumed that it was used for animal sacrifice rituals as its cartilage was preserved. The fact that animal remains were found inside the well suggested that they were either items that were thrown away during the well’s use or items that were thrown in during its disposal. They might have been made through some ritualistic acts. In animal archaeology, animal remains not only provide information on food resources used in the era but also serve as materials that show the lifestyle of that society. Therefore, through anatomical analysis of animal remains and continuous data accumulation, we could understand the social life of the era when humans used animals.

Anatomical investigation results of N. procyonoides bone relics excavated from the well site of Gasan-ri, Ibanseong-myeon, Jinju are summarized as follows. Of a total of 447 animal bone fragments, 59 (13.2%) were classified as N. procyonoides bones. These N. procyonoides bones accounted for 4.83% of the total weight (975.30 g). They were estimated to be 5 to 6 weeks old. They were identified as 2 animals. These N. procyonoides bones were classified into skull, vertebrae, ribs, hip bones, forelimbs, and hindlimbs. A fracture was observed near the bregma of the skull. Since an intact individual was found in the well site, it could be assumed that it was used for animal sacrifice rituals. This study provides basic data for understanding the lifestyle of people based on animals used by them at that time through N. procyonoides bones presumed to be relics of the Three Kingdoms period.