MORPHOMETRIC ANALYSIS OF THE CRANIAL CAVITY AND THE OCCIPITAL REGION OF THE SKULL IN AUROCHS (BOS PRIMIGENIUS BOJANUS 1827)

Witold Brudnicki¹, Włodzimierz Nowicki¹, Adam Brudnicki¹, Benedykt Skoczylas¹, Krzysztof Kirkiłło-Stacewicz¹, Jan Wach¹, Karol Grzywacz^2
1 Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
² Department of Animal Morphology and Hunting, University of Technology and Life Sciences in Bydgoszcz, Poland

ABSTRACT

The skull was found in the Tuchola Forest (Kuyavia and Pomerania Province) in the area of Tuchola. The skull was almost complete, with only a part of the incisive bone and the mandible missing. Observations and measurements allowed to broaden the knowledge about the next morphometric data concerning these extinct species. The capacity of the cranial cavity in investigated species was 710 cm³  and was much bigger then capacity of other Bovidae except for European bison (more than 12 years). The inner length of the cranial cavity measured from the rooster comb to the bregma point was 155 m. The comparison of the capacity of the cranial cavity in auroch with domestic cattle proves the higher capacity of the cranial cavity in auroch. Considering the auroch as the ancestor of the cattle it confirms  Bogolubski's (1968) thesis that wild game has the higher capacity of the cranial cavity in comparison with the related domestic animals.

Key words: aurochs, skull, morphometry, cranial cavity, occipital region.

INTRODUCTION

The applicable literature on craniometric features offers e.g. information on the cranial cavity parameters. The authors usually use the term to describe the cavity sheltering brain, namely, as interpreted by Roskosz (1973), the brain cavity of the skull. The volumetric measurement of the cranial cavity, as it is referred to in the anatomy terminology, usually illustrates the effect of the brain on the shape of the skull. Having the bone material at our disposal and investigating the volume of the cranial cavity, we acquire the knowledge on the volume of the brain, found it in that cavity. Obviously the volume of the cranial cavity is not the same as the volume of the brain, as it does not consider e.g. meninges or subarachnoid spaces, however, for the purpose of the comparative study it is surely applicable, especially in the extinct species after which there have remained only relatively durable parts; namely bones. Tracking down the development cycle of the skull in mammals, many authors focus on the phenomenon of decreasing volume of the cranial cavity in older males, Mystkowska (1966) observed such a phenomenon in European red deer, Roskosz (1973) in European bison.

The comparison of the volume of the cranial cavity in domesticated animals and their wild ancestors is greatly interesting. Bogolubski (1959) claims that in domestic animals and those kept in the zoos the brain is smaller and so their cranial cavity is smaller than in the animals they are related to living in the wild, which coincides with the reports by Brudnicki (2005) investigating the cranial cavity volume in domestic pig and wild boar. With that in mind, contrasting the cranial cavity volume in aurochs and in domestic cattle is extremely interesting. The reports on that extinct species most frequently cover most abundantly preserved parts, namely bones, especially the skull. Gedymin (1965) and Chrzanowska (1971) Frąckowiak et al. (2004) described the craniometric features in aurochs based on the material available. Those authors did not mention the cranial cavity volume in aurochs. Neither was such information provided by van Vuure (2005) in his very detailed study of the morphology and ecology in aurochs. The parameter in another Bovinae representative, in European bison, was investigated in detail by Roskosz (1973) who determined the volume of the cranial cavity both in males and in females in various age classes. Just for the sake of the comparison, he also included the information on the volume of the cranial cavity in American bison, wisentbison and in cattle.

With an almost complete skull at our disposal, the authors of the present paper have decided to investigate the volume of the cranial cavity in aurochs and to compare the results with those reported for this parameter in other Bovidae representatives.

MATERIAL AND METHODS

The research involved the skull in aurochs from the Tuchola Forest, owned by the Agrotechnical Schools in Tuchola. The skull was almost complete, with only a part of the incisive bone and the mandible missing (Fig. 1).

Figure 1. Aurochs skull from the Tuchola Forest

Its condition was good enough to determine the cranial cavity volume. The volume of the cranial cavity was defined by filling it with rape grains having sealed the natural openings with plastic, and then determined its volume in the calibrated cylinder at the accuracy up to 1 cm³. The measurement was made three times and then the mean value was calculated. The inner length of the cranial cavity was measured from the crista galli of the ethmoid bone to point Basion located on the parabasal border of the occipital foramen magnum in the median plane.

For information and comparison purposes, there were also investigated the volumes of the cranial cavity in 4 European bison specimens collected by the Department of Animal Morphology and Hunting, the University of Technology and Life Sciences in Bydgoszcz, and 10 domestic cattle individuals from the same collection. There were investigated the relative volume applying the formula:

Relative volume = cranial cavity volume × 100 / length of the skull base

RESULTS

Analysing the morphological characteristics of the occipital region in aurochs, one shall note the species-specific, extremely strongly developed protuberantia intercornualis, changing laterally into huge corneal processes. Both the squamous part of the occipital bone and the caudal surface of protuberantia intercornualis show an uneven surface with numerous sulci and osseous borders. They must have been strong attachments for the neck muscles. Along the temporal border of the squamous part of the occipital bone there is a visible gutter-like depression, formed by temporal bones - Fig.2.

Figure 2. Skull back-of-neck surface in aurochs and occipital foramen magnum

The data on the cranial cavity volume in aurochs together with the information on other Bovidae family representatives reported by Roskosz (1973) are given in Table 1.

Table 1. Absolute and relative cranial cavity volume in aurochs and other Bovidae.

	N	Absolute volume [cm3]	SD	Relative volume	SD
Aurochs	1	710	-	137.9	-
European bison (Department's collection )	3	630	-	149.7	-
Cattle (Department's collection)	10	520	12.36	122.6	8.36
Male European bison (Roskosz 1973)	22	734	7.71	151.7	7.10
Female European bison (Roskosz 1973)	19	679	11.14	151.0	7.46
Wisentbison (Roskosz 1973)	2	645	-	137.8	-
American bison (Roskosz 1973)	3	605	-	137.2	-
Cattle (Roskosz 1973)	10	545	14.86	123.7	7.83

The metrical characteristics of that skull fragment together with the parameters of the occipital foramen magnum are given in Table 2.

Figure 3. Foramen magnum in aurochs

Table 2. Metrical characteristics of the occipital region of the skull in aurochs.

	Measurements
1.	Skull height	238 mm
2.	The greatest width of mastoid processes	344 mm
3.	Occipital condyles width	159 mm
4.	Occipital bone height	108 mm
5.	Occipital foramen magnum height	45 mm
6.	Maximum width of the occipital foramen magnum	46 mm
7.	Inner length of cerebral cavity	155 mm

DISCUSSION

Analysing the volume of the cranial cavity in aurochs, as compared to other Bovidae family representatives reported by Roskosz (1973), it can be noted that European bison males over 12 years old reached a greater cranial cavity volume and it was, on average, 734 cm³, whereas the European bison females, American bisons and wisentbisons showed a smaller cranial cavity volume. The comparison of this parameter in aurochs and domestic cattle is especially interesting. As reported by Roskosz (1973), the average cranial cavity volume in cattle is 545 cm³ and so the difference is considerable. As for cattle, the data presented concern, however, cows, while both the craniometric features of the skull and corneal processes, which in aurochs are an important indicative feature, demonstrate that we deal with a male.

A comparison of the index of the relative cranial cavity volume in aurochs with a similar index for other Bovidae reported by Roskosz (1973), one can find that it scores lower than the representatives of both sexes in European bison, and a comparable with the value of that index in American bison and wisentbison. And in that case the relative volume index in aurochs is definitely greater than that calculated for cattle.

The value of that index is mostly determined by the length of the skull base. In European bison, depending on the age, it ranges from 413 cm to 492 cm, while in aurochs it is as much as 515 cm.

Due to missing literature coverage, it is impossible to refer the present results to the research of this type performed in other aurochs individuals. The researchers usually deal with incomplete skulls and most probably it is not possible to determine the cranial cavity volume due to damage. The skull of the aurochs from the Tuchola Forest is complete enough for that parameter to be determined. The inner length of the cerebral cavity measured from the crista galli to point Bregma is 155 mm. The parameter is helpful to define the animal height in the interscapular region using the Wyrost formula (1967). The comparisons of the cranial cavity volume in aurochs with domestic cattle point to a much greater cranial cavity volume in aurochs. Assuming that aurochs was the ancestor of cattle, the fact confirms the thesis by Bogolubski (1968) who claims that animals living in the wild have a greater cranial cavity volume than the related domestic animals they are related to. Similar results were reported by Brudnicki (2005) who compared the cranial cavity volume in wild boar and domestic pig in comparable age classes.

REFERENCES

1. Bogolubski G., 1968. Pochodzenie i ewolucja zwierząt domowych. PWRiL. Wawszawa.228-243.
2. Brudnicki W., 2005. Comparison of Craniometric Features and Cranial Cavity Volume in Domestic Pig (Sus scrofa forma domestica) and Wild Boar (Sus scrofa) in View of Development'' Folia Biologica (Kraków), vol.53: 1-6.
3. Chrzanowska W., 1971. Kilka uwag o czaszkach tura (Bos primigenius Bojanus 1827). Przegl. Zool. XV, 1:91-97.
4. Gedymin T., 1965. Tur (Bos primigenius Bojanus 1827) na ziemiach Wielkopolski i Kujaw. Rocz. WSR w Poznaniu, XXV; 21-37.
5. Frąckowiak H., Makowiecki D., Kulawik M., 2004. Kości czaszki  tura (Bos primigenius Bojanus 1827) z miejscowości Nowy Jaromierz. Rocz. Nauk. Zoot., T.31, z.1: 155-161.
6. Mystkowska E., 1966. Morphological variability of the skull and body weight of the red deer. Acta Theriol. 11, 5:129-194.
7. Roskosz T., 1973. Studium nad kanałem kręgowym (Canalis vertebralis) żubra, Bison bona sus (Linnaeus 1758) Zeszyty Naukowe AR w Warszawie Rozprawy naukowe 29: 5-58.
8. Vuure van T., 2005. Retracing the Aurochs. History. morphology and ecology of the Aurochs (Bos primigenius) an Extinct Wild Ox. Pensoft. Sofia.
9. Wyrost P., Kucharczyk J., 1967. Versuvh der Bestimmung der Widerristhöhe des Hundes mittels der inneren Hirnhöhlenlänge. Acta Theriol.12, 9: 105-110.

Accepted for print: 21.12.2011

---

Witold Brudnicki
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: anat@utp.edu.pl

Włodzimierz Nowicki
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: wlodek_novika@interia.eu

Adam Brudnicki
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: brudnicki.adam@gmail.com

Benedykt Skoczylas
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: anat@utp.edu.pl

Krzysztof Kirkiłło-Stacewicz
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: krzysztof.stacewicz@o2.pl

Jan Wach
Department of Animal Physiology, Zoophysiotherapy and Feeding, Faculty of Animal Breeding and Biology, UTP University of Science and Technology, Bydgoszcz, Poland
Bernardyńska 6
85-029 Bydgoszcz
Poland
email: janwach82@poczta.onet.pl

Karol Grzywacz
Department of Animal Morphology and Hunting,
University of Technology and Life Sciences in Bydgoszcz, Poland
Bernardyńska 6, 85-029 Bydgoszcz, Poland
email: kgz@tuchola.pl

---

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.

---

Main  -  Issues  -  How to Submit  -  From the Publisher  -  Search  -  Subscription