A Taphonomic Study of Crocodylus porosus (Crocodylidae) and Tomistoma schlegelii (Gavialidae) Remains from Western Sarawak, Malaysian Borneo: Applications for Public Education

  • Ruhana Hassan
  • Nur Fatimah Mohd Azizi
  • Muhammad Amirul Arib Md Adzhar
  • Mohd Izwan Zulaini Abdul Gani
  • Rambli Ahmad
  • Charles Leh Moi Ung


This study documented details of the dentitions, skulls and other skeletal remains of Crocodylus porosus and Tomistoma schlegelii, from western part of Sarawak, Malaysian Borneo. The remains of both reptiles were exhumed, followed by standard cleaning procedures and then detail morphological assessments were carried out accordingly. Both species show similar structure of vertebral columns, but T. schlegelii has the following unique structures: a long and narrower snout, D-shaped eye sockets, long and sharp pointed protruding quadratojugal bones, straight maxillae and dentary, a smooth surfaced skull, elongated triangular suborbital fenestrae, round shaped internal nares and visible supraoccipital from a dorsal view. C. porosus has heterodont dentition with blunt-pointed and irregular size of teeth whereas T. schlegelii has almost homodont dentition with sharp and similar size teeth. This is the first collection of teeth, skulls and other skeletal remains of both species obtained from Sarawak, and the materials have been used regularly to educate the public through science exhibitions, hoping they will spark the interests of young budding scientists to be involved in wildlife taphonomic studies in the future.
Keywords: Crocodylus porosus, dentition, reptile, skeletal remain, Tomistoma schlegelii


Bezuijen, M. R., Shwedick, B., Simpson, B. K., & Stuebing, R. B. (2014). Tomistoma schlegelii. The IUCN Red List of Threaten Species Version 2014.3. Retrieved June 10, 2017, from www.iucnredlist.org.

Bezuijen, M. R., Shwedick, B. M., Sommerlad, R., Stevenson, C., & Stuebing, R. B. (2010). Status survey and conservation action plan. Darwin: Wildlife Management Pty Limited.

Bezuijen, M. R., Hartoyo, P., Elliot, M., & Baker, B. A. (1997). Project Tomistoma. Second report of the ecology of the false gharial (Tomistoma schlegelii) in Sumatera. Darwin: Wildlife Management International Pty Limited.

Bezuijen, M. R., Cannucciari, P., Ramono, W. S., & Webb, G. J. W. (1995). Project Tomistoma. Field trip to Palembang, Sumatera Selatan, Indonesia. 14 March - 3 April: Trip Report. Wildlife Management International Pty Limited.

Britton, A. (2012). Current distribution of Crocodylus porosus. Retrieved July 10, 2017, from www.crocodilian.com. Cox, J. H., & Gombek, F. (1985). A preliminary survey of the crocodile resource in Sarawak East Malaysia," IUCN/WWF Project MAL 74/85, World Wildlife Fund Malaysia & the National Parks and Wildlife Office, Forest Department, Sarawak, Malaysia.

Enax, J., Fabritius, H., Rack, A., Prymak, O., Raabe, D., & Epple, M. (2013). Characterization of crocodile teeth: Correlation of composition, microstructure and hardness. Journal of Structural Biology, 184, 155-163.


Ferraro, J. V., & Binetti, K. M. (2014). American alligator proximal pedal phalanges resemble human finger bones: Diagnostic criteria for forensic investigators. Forensic Science International, 240, 151.e1-151.e7.


Gani, M. I. Z.A. (2014). Population Density, Human-Crocodile Conflict and Genetic Variations among Saltwater Crocodile, Crocodylus porosus in Sarawak (master's thesis). Universiti Malaysia Sarawak, Sarawak, Malaysia.

Gani, M. I. Z. A., & Hassan, R. (2013). Crocodiles of Sungai Sibu Laut. In L. Nyanti, N. Ismail, R. Hassan, S. Mohamad & S. A. K. A. Rahim (Eds.), Aquatic Science Colloquium 2012 Monograph (pp. 13-18).

Grigg, G., & Gans, C. (1993). Fauna of Australia Vol 2A Amphibia and Reptilia. Canberra, Australia: Australian Government Publishing Service.

Gunther, A. C. (1861). Reptiles of British India (pp. 61-63). Janpath, New Delhi: Oxford Publication.

Hassan, R., Md Adzhar, M. A. A., Gani, M. I. Z. A., & Ahmad, R. (2018) Assessment of wild saltwater crocodile population in Bako River, Western Sarawak, Malaysian Borneo for potential ecotourism industry. Malaysian Applied Biology, 47(1), 131-138.

Hassan, R., Ahmad, R., Adzhar, M. A. A., Gani, M. I. Z. A., Ayob, A., & Zainuddin., R. (2016). Notes on the wild Tomistoma populations in western Sarawak, Malaysian Borneo. International Journal of Ecology. Article ID 4357623, 7 pages. http://dx.doi.org/10.1155/2016/4357623


Hassan, R., & Gani, M. I. Z. A. (2013). Crocodiles in western of Sarawak, Malaysia. Proceedings of the 22nd Working Meeting of the IUCN SSC Crocodile Specialist Group, World Crocodile Conference (pp. 90-95). Negombo, Sri Lanka.

Hastings, A. K., & Dooley, A. C. (2017). Fossil-collecting from the middle Miocene Carmel Church Quarry marine ecosystem in Caroline County, Virginia. Field Guides, 47, 77-88.


Hilderbrand, M. (1995). Analysis of vertebrate structure (4th ed.). New York, NY: John Wiley & Sons Inc.

Liem, K. F., Bemis, W. E., Walker, W. F., & Grande, L. (2001). Functional anatomy of the vertebrates (3rd ed.). Belmont, CA: Brooks/Cole-Thomson Learning.

Md Adzhar, M. A. A., & Hassan, R. (2017). Relationships among Tomistoma schlegelii in Malaysia Based on Cyt b-Control Region Gene Analysis. International Journal of Zoology, 2017. Article ID 5431041, 6 pages. https://doi.org/10.1155/2017/5431041


Mueller-Töwe, I. J. (2006). Anatomy, phylogeny, and palaeoecology of the basal Thalattosuchians (Mesoeucrocodylia) from the Liassic of Central Europe (Doctor of Philosophy thesis). Gutenberg University of Mainz, Mainz, Germany.

Pine, A. (2013). Tomistoma, False Gharial, Sunda Gavial (Tomistoma schlegelii). A Report for Mohamed bin Zayed Species Conservation Fund, project number 12255301. Retrieved June 10, 2017, from http://www.speciesconservation.org/case-studies-projects/tomistoma-false-gharial sunda.

Ritchie, J., & Jong, J. (2002). Man Eating Crocodiles of Borneo. Kota Kinabalu, Sabah: Natural History Publications (Borneo).

Shaker, N. A., & El-Bably, S. H. (2015). Morphological and Radiological Studies on the Skull of The Nile Crocodile (Crocodylus niloticus). International Journal of Anatomy and Research, 3(3), 133-140.


Stuebing, R. B., Bezuijen, M. R., Auliya, M., & Voris, H. K. (2006). The current and historic distribution of Tomistoma schlegelii (the False Gharial) (Müller, 1838) (Crocodylia, Reptilia). The Raffles Bulletin of Zoology, 54(1), 181-197.

Stuebing, R. B., Sah, S. A. M., Lading, E., & Jong, J. (2003). The status of Tomistoma schlegelii (Mueller) in Malaysia. Proceedings of the 17th Working Meeting of the IUCN-SSC Crocodile Specialist Group (pp. 136-140). IUCN: Gland, Switzerland.

Webb, G. J. W., Manolis, S. C., & Brien, M. L. (2010). Saltwater Crocodile, Crocodylus porosus. In S. C. Manolis & C. Stevenson (Eds.), Crocodiles: Status Survey and Conservation Action Plan (3rd ed.) (pp. 99-113). Crocodile Specialist Group: Darwin.

Willis, R. E., McAliley, L. R., Neely, E. D., & Densmore, L. D. (2007). Evidence for placing the false gharial (Tomistoma schlegelii) into the family Gavialidae: inferences from nuclear gene sequences. Molecular Phylogenetics and Evolution, 43(3), 787-794.


Zaini, M. K., Ripot, S., Ubang, C. K., Francis, R., & Simon, A. M. (2014). Crocodile Survey at Kuching, Samarahan and Sri Aman Division, Sarawak, Malaysia. Borneo Crocodile Forum, Sarawak Malaysia.

How to Cite
Hassan, R., Mohd Azizi, N. F., Md Adzhar, M. A. A., Abdul Gani, M. I. Z., Ahmad, R., & Moi Ung, C. L. (2018). A Taphonomic Study of Crocodylus porosus (Crocodylidae) and Tomistoma schlegelii (Gavialidae) Remains from Western Sarawak, Malaysian Borneo: Applications for Public Education. Trends in Undergraduate Research, 1(1), a23-32. https://doi.org/10.33736/tur.1139.2018
Resource Science and Technology