Anat. Histol. Embryol. 35, 53–56 (2006) Ó 2005 Blackwell Verlag, Berlin ISSN 0340–2096
doi: 10.1111/j.1439-0264.2005.00659.x
Department of Anatomy, Faculty of Veterinary Medicine, University of Firat, Elazıgˇ, Turkey
Comparative Macroanatomical Study of the Neurocranium in some Carnivora ¨ zdemır3 and E. U ¨ nsaldi1 M. Karan1*, S. Tımurkaan2, D. O Addresses of authors: 1Department of Anatomy, Faculty of Veterinary Medicine, University of Firat, Elazıgˇ; 2Department of Histology and Embryology, Faculty of Veterinary Medicine, University of Firat, Elazıgˇ; 3Department of Anatomy, Faculty of Veterinary Medicine, University of Ataturk, Erzurum, Turkey; *Corresponding author: Tel.: +90 424 23 7000/6453; fax: +90 424 238 8173; e-mail:
[email protected] With 3 figures and 1 table
Received October 2004; accepted for publication May 2005
Summary
Materials and Methods
This study was carried out to investigate the specific anatomical features of the neurocranium of the skull of the dog, cat, badger, marten and otter. Twenty-five animals (five from each species) were used without sexual distinction. The neurocranium consists of os occipitale, os sphenoidale, os pterygoideum, os ethmoidale, vomer, os temporale, os parietale and os frontale. The processus paracondylaris is projected ventrally in the cat, dog, marten and badger, and caudally in the otter. Two foramina were found laterally on each side of the protuberantia occipitalis externa in the otter, and one foramen was found near the protuberantia occipitalis externa in the badger. Foramen was not seen in other species. Paired ossa parietalia joined each other at the midline, forming the sutura sagittalis in the badger, dog, otter and cat while it was separated by the linea temporalis in the marten. The os frontale was small in otters, narrow and long in martens, and quite wide in cats and dogs. The bulla tympanica was rounded in the marten, dog, cat and badger, dorsoventral compressed in otter, and it was very large in all species examined. These observations represented interspecies differences in the neurocranium of marten, otter, badger, cat and dog.
A total of twenty-five animals including five cats, five kangal dogs, five badgers, five martens and five otters were used without sexual distinction in this study. The animals were killed with pentathol (60 mg/kg, i.v.), then the head was separated from the body. Each head was boiled in water. The skull specimens were prepared by removing the soft tissue from the bones. The observation was carried out by the naked eye, and photographs were taken as required. Maceration of bones was carried out according to established protocols (Tas¸bas¸ and Tecirliogˇlu, 1966). For terminology, Nomina Anatomica Veterinaria (International Committee on Veterinary Gross Anatomical Nomenclature, 1994) was used.
Introduction Neurocranium consists of os occipitale, os sphenoidale, os pterygoideum, os ethmoidale, vomer, os temporale, os parietale and os frontale (Getty, 1975; Evans, 1979; Tecirliogˇlu, 1983; Nickel et al., 1987; Dursun, 1994), and it is the part of the skull which protects the brain (Mcclure et al., 1973). The dog (Canis familiaris), cat (Felis domesticus) belonging to Canidae is taxonomically different from the badger (Meles meles), marten (Martes foina) and otter (Lutra lutra), a mustelid species (Kuru, 1987; Demirsoy, 1992). In general, animal remains are mostly found as bone fragments, and it is difficult to distinguish between the bones of carnivora. Therefore, it is important to obtain the basic data on the skeleton of the carnivora. Concerning the bones of these species, only a few studies on the skulls of some carnivora (badger, otter) have been reported (Yılmaz et al., 2000; Dinc, 2001). Our purpose is to obtain the basic data necessary to identify skulls of some carnivora. This study was carried out to investigate the specific anatomical features of the neurocranium of the skull of the dog, cat, badger, marten, otter with comparative anatomical consideration (Table 1).
U. S. Copyright Clearance Center Code Statement:
Results Os parietale Paired ossa parietalia joined each other at the midline, forming the sutura sagittalis in the badger, dog, otter and cat while it was separated by the linea temporalis in the marten. The parietal bones were dorsolaterally convex in the dog, badger and otter, round in the marten and cat, and covered most of the dorsum of the cranial cavity in all species. The linea temporalis was short in the badger and dog, and extended from the crista sagittalis externa to the processus zygomaticus of os frontale. The linea temporalis was long, and ran rostrally from the squamous part of the occipital bone to the zygomatic process of the frontal bone in the otter and marten. However, the linea temporalis was insignificant in the cat. The crista sagittalis externa was short and restricted to the caudal part of the cranium in the cat and marten. There was a prominent crista sagittalis externa which was continued upon the frontal bones in the badger and dog, and the rostral end of the external sagittal crest was narrower and thinner than the caudal end. The crista sagittalis externa was absent in the otter (Fig. 1). Os interparietale The interparietal bone fused with the squamous part of the occipital bone and parietal bones in badger. However, os interparietale was a median bone situated between the squama occipitalis and the os parietalia in other species. The interparietal bone was triangular in shape.
0340–2096/2006/3501–0053$15.00/0
www.blackwell-synergy.com
M. Karan et al.
Developed Wide, centrally depressed, more or less concave Joined the midline, convex
Extended obliquely
Developed Wide, protruded dorsally Joined the midline, convex
Extended obliquely
Protruded laterally Less developed Small, flat
Continued upon the frontal bones Ventrally, long Dog
Prominent, no foramen
Ventrally, long Badger
Indistinct, one foramen
Continued upon the frontal bones
Extended from the squamous part of the occipital bone to the zygomatic process of the frontal bone Extended from the external sagittal crest to the zygomatic process of the frontal bone Extended from the external sagittal crest to the zygomatic process of the frontal bone Caudally, long Otter
Indistinct, two foramina
Restricted to the caudal part of the cranium Absent Indistinct, no foramen Ventrally, short Cat
Marten
Joined the midline, convex
Protruded laterally Prominent Wide, protruded dorsally
Narrow, long, slightly protruded Separated by the linea temporalis, round
Joined the midline, round
Protruded laterally
Os frontale Os parietale
Linea temporalis Extended from the squamous part of the occipital bone to the zygomatic process of the frontal bone Insignificant Crista sagittalis externa Restricted to the caudal part of the cranium Protuberantia occipitalis externa Indistinct, no foramen Proc. paracondylaris Ventrally, short Species
Table 1. Comparison of some structures in neurocranium of marten, cat, otter, badger and dog
Structure
Proc. zygomaticus of the os frontale Developed
Arcus zygomaticus
54 Os frontale
Os frontale was small in otter, narrow and long in marten, and quite wide in cat and dog. Os frontale protruded dorsally in badger and cat, it was slight in marten, and flat in otter. The frontal region was centrally depressed, and was more or less concave in profile in the dog. The external surface of the frontal bone was crossed by the linea temporalis. The foramen supraorbitale was absent in all the species. The frontal zygomatic process was developed in the badger, marten and dog. The processus zygomaticus of os frontale was less developed in the otter. However, in the cat a prominent zygomatic process was observed. The supraorbital margin was incomplete in the dog, marten, otter and badger, but complete in the cat (Fig. 1). Os occipitale The processus paracondylaris (Fig. 2) was projected ventrally in the cat, dog, marten and badger, caudally in the otter, and it was shorter in the marten and cat than in the dog, otter and badger. A prominent nuchal crest was observed on the os occipitale in all species. The protuberantia occipitalis externa was directed towards the foramen magnum as an indistinct crista occipitalis externa in the cat, marten, otter and badger; however there was a prominent crista occipitalis externa in the dog. Two foramina were found laterally on each side of the protuberantia occipitalis externa in otter, and one foramen was found near the protuberantia occipitalis externa in badger. A name for these foramina was not found in Nomina Anatomica Veterinaria. No foramen was seen in other species. Dorsal condylar fossa was marked in the cat, otter and badger. The squamous part of the occipital bone was the widest in the otter. The shape of foramen magnum was almost oval in all species. Striking features on the basal surface of the cranium (Fig. 3) were the width and flatness of the basilar part of the occipital bone in the dog, otter and marten. However, the base of the occipital bone was ventrally concave in the badger. The canalis n. hypoglossi and the foramen condylare were considerably pronounced in all species. The foramen jugulare was bigger in the cat and otter than in badger, dog and marten. The muscle tubercles were visible in the cat. Os temporale The bulla tympanica was rounded in the marten, dog, cat and badger, dorsoventral compressed in otter, and was very large in all species examined. The processus muscularis was thin and long in the dog and otter, and inconspicuous in the badger, cat and marten. The processus mastoideus was better developed in the badger compared examined species with other. The processus styloideus was absent in all the species. The processus retroarticularis was found as a prominent protuberance extending to cranial in the cat, otter, badger and marten, and to ventral in the dog. The articular surface for the condyle of the mandible consisted of a transverse groove, which was continued upon the rostral part of the large retroarticular process. The tuberculum articulare was observed as a small elevation on the rostral border of the mandibular fossa in the cat, otter and badger. There was no articular tubercle in the other species. In all examined species the process zygomaticus
Anatomical Study of Neurocranium in Carnivora
55
Fig. 1. Dorsal view of the cranium. (a) marten; (b) cat; (c) otter; (d) badger; (e) dog. White arrow: crista sagittalis externa; black arrow: the processus zygomaticus of os frontale.
Fig. 2. Caudoventral view of the cranium. (a) marten; (b) cat; (c) otter; (d) badger; (e) dog. Arrow: the processus paracondylaris.
of temporal bone and the process temporalis of the zygomatic bone formed the arcus zygomaticus. The arcus zygomaticus protruded laterally in the marten, cat and otter, but it extended obliquely forward in the badger and dog (Fig. 3). The other bones joining the construction of the neurocranium were not evaluated as they possessed no differences among the species.
Discussion Neurocranium is an important part of the head which protects the brain. The caudal aspect of the neurocranial portion of the skull is formed by the occipital bone. The dorsal surface of the neurocranium consists of a paired parietal and paired frontal bones (Yı et al., 1998). The temporal bone is the most
M. Karan et al.
56
Fig. 3. Ventral view of the cranium. (a) marten; (b) cat; (c) otter; (d) badger; (e) dog. Arrow: the bulla tympanica; arrowhead: the arcus zygomaticus.
prominent bone which forms the lateral part of the neurocranium (Mcclure et al., 1973). Dinc (2001) described that the crista sagittalis externa was developed, os interparietale fused with squama occipitalis and os parietale, the processus mastoideus was marked in the badger. Similar findings were observed in this study. The shape of foramen magnum was almost oval in badger and raccoon dog (Hidaka et al., 1998). In our study, the shape of foramen magnum was also oval in all species examined. Yılmaz et al. (2000) reported that two foramina were found laterally on each side of the protuberantia occipitalis externa in otter. In this study two foramina were also present in otter, however one foramen was found in the badger, and in other species no foramen was seen. It was reported that the frontal zygomatic process was angular shape in raccoon dog, less developed in badger (Hidaka et al., 1998), and absent in badger (Dinc, 2001) and otter (Yılmaz et al., 2000). The present study found that the frontal zygomatic process was less developed in otter, slightly developed in the badger and dog, and was well developed in cat. According to Dinc (2001) the supraorbital foramen was absent in the badger and Yılmaz et al. (2000) reported the same in otter. In our study, the foramen supraorbitale was also absent in all species. Distinguishable differences in bones forming the neurocranium were observed among the carnivora. In this study we tried to document the similarities and differences of these bones in carnivora. This study focused on the general features of the bones forming neurocranium. In conclusion, macroscopically the interspecies differences were found in the marten, otter, badger, cat and dog bones.
References Demirsoy, A., 1992: Yas¸amın Temel Kuralları. Ankara: Meteksan Anonim S¸irketi, pp. 759–760. _ Dinc, G., 2001: Porsuk (Meles meles) IskeletSistemi U¨zerinde MakroAnatomik Aras¸tırmalar III. Skeleton Axiale. F.U¨. Sagˇlık Bil. Derg. 15, 175–178. Dursun, N., 1994: Veteriner Anatomi I. Ankara: Medisan Yayınevi, pp. 73–94. Evans, H. E., 1979: Chrıstensen Miller’s Anatomy of the Dog. Philadelphia, PA: W. B. Saunders Company, pp. 148–157. Getty, R., 1975: The Anatomy of the Domestic Animals, Vol. 1, 2, 5th edn. Philadelphia, PA: Saunders Company, pp. 1427–1482. Hidaka, S., M. Matsumoto, H. Hiji, S. Ohsako, and H. Nishinakagawa, 1998: Morphology and morphometry of skulls of raccoon dogs, Nyctereutes procyonoides and badgers, Meles meles. J. Vet. Med. Sci. 60, 161–167. International Committeeon Veterinary Gross Anatomical nomenclature. 1994: Nomina Anatomica Veterinaria, 4th edn. Gent: World Association of Veterinary Anatomists. Kuru, M., 1987: Omurgalı Hayvanlar. Erzurum: Atatu¨rk U¨niv. Basımevi, pp. 577–580. Mcclure, R. C., M. J. Dalman, and P. G. Garrett, 1973: Cat Anatomy, An Atlas, Text and Dissection Guide. Philadelphia, PA: Lea Febiger. Nickel, R., A. Schummer, and E. Seiferle, 1987: The Anatomy of the Domestic Animals, Vol. 1. Berlin: Verlag Paul Parey. Tas¸bas¸, M., and S. Tecirliogˇlu, 1966: Maserasyon Teknigˇi U¨zerinde Aras¸tırmalar. J. Fac. Vet. Med. U¨niv. Ankara 12, 324–330. _ Tecirliogˇlu, S., 1983: Sırtlan ve Ko¨pegˇin IskeletKemikleri U¨zerinde Makro-Anatomik Aras¸tırmalar. Ankara U¨niv. Vet. Fak. Derg., 30, 149–166. Yı, S. J., H. S. Lee, K. S. Kım, and T. C. Kang, 1998: The comparative anatomical study of the parietal region of the skull of the Korean native goat (Capra Hircus). Anat. Histol. Embryol. 27, 323–325. Yılmaz, S., G. Dinc¸, and B. Toprak, 2000: Macro-Anatomical Investigations on Skeletons of Otter (Lutra lutra). III: Skeleton Axiale. Veterinarski Arhiv. 70, 191–198.
