Was the crocodile that Han Yu drove away the Han Yu crocodile?

In 819 AD, during the reign of Emperor Xianzong of the Tang Dynasty, Han Yu was demoted to the post of governor of Chaozhou. Soon after arriving there, he discovered that giant crocodiles several meters long often appeared here, attacking nearby pedestrians and livestock. He ordered sheep and pigs to be thrown into the river as sacrifices to the giant crocodiles, hoping to eliminate the crocodile problem.

Of course, crocodiles did not disappear, but Han Yu won popularity with his actions during his tenure, and even the mountains and rivers in Chaozhou were named Han after him. His "Sacrifice to Crocodiles" also became the most famous story about the "crocodile plague" in ancient Lingnan.

The Han Wenggong Temple in Chaozhou was first built during the Southern Song Dynasty in memory of Han Yu. The Bijia Mountain where the Han Wenggong Temple is located is also known as Han Mountain, and the Han River flows under the mountain.

In March this year, a research team from Hefei University of Technology published a paper: They discovered an extinct prehistoric giant crocodile in Guangdong and named it " Chinese Hanyu Crocodile " (Hanyusuchus sinensis).

We are still not sure whether the crocodiles Han Yu drove away were the Han Yu crocodiles. However, Han Yu's sacrificial crocodiles and the Han Yu crocodiles together restore for us the long-lasting battle between humans and crocodiles that once took place in Lingnan .

Restoration of Han Yu's crocodile｜Hikaru Amemiya

Chinese Crocodile

Hanyusuchus is an independent new genus, and the Chinese Hanyusuchus (H.sinensis) is the only member of this genus. The specific nickname "sinensis" means "from China" in Latin.

Among the crocodiles that exist today, the closest relative to the Hanyu crocodile is the Ganges crocodile , which belongs to the same family as the Alligatoridae; the more familiar Yangtze alligator and Siamese crocodile belong to the Alligatoridae and Crocodileidae, respectively, and are more distantly related to the Hanyu crocodile. The difference in size is also great. The length of an adult Yangtze alligator is usually no more than 2 meters, but according to the restoration data inferred from fossils, an adult Hanyu crocodile can reach 6 meters in length (the giant crocodile recorded in historical books is "more than two feet long", which is about 6.5 to 7 meters in length), which is comparable to the largest reptile in existence, the saltwater crocodile.

The saltwater crocodile (Crocodylus porosus) is the largest crocodile alive | Molly Ebersold / the St. Augustine Alligator Farm

Looking at all the crocodiles that have existed in history, the closest relatives to the Hanyu crocodile are the Toyotama crocodile and the Penghu crocodile - the former lived in the Japanese archipelago during the Pleistocene, and the latter lived in the Penghu Islands of Taiwan, China during the Miocene. The upper jaws of these three extinct crocodiles all have 16 teeth, and the seventh tooth is the largest. This tooth distribution feature is not found in other crocodiles, which shows that there is an extraordinary relationship between these three species from different regions.

The Hanyu crocodile is a typical transitional species, retaining the hybrid features of early cut-snouted crocodiles (such as the current Malayan crocodile) and later long-snouted crocodiles (such as the gharial). Because the 18 teeth on the mandible of the Hanyu crocodile are similar to those of the Malayan crocodile, they were even mistaken for some extinct giant Malayan crocodile .

The Malayan alligator (Tomistoma schlegelii), the only living species of the genus Tomistoma｜Achim Raschka / Wikimedia Commons

In 1963, a crocodile skull fossil was accidentally unearthed in a fish pond near Guizhou People's Commune, Shunde County, Foshan City, Guangdong Province. In the following decade, at least five batches of fossils were discovered in the Pearl River Delta region, including skulls, intradermal bones, trunk fragments, etc. Among them, there were both adult and subadult specimens, which were identified as belonging to the same species. Regardless of the number or completeness of the fossils, the fossil data of Hanyu crocodile can be said to be complete. However, due to the scientific research level at the time and the convergent evolution of the appearance, these fossils were eventually regarded as large Malayan crocodiles and did not attract enough attention.

It was not until nearly 60 years later that these six specimens attracted the attention of scientists again and finally got their own name : they were different from the Malayan crocodiles, possessed more unique developmental characteristics of members of the Giraffinae subfamily, and were significantly differentiated from several other existing genera, and were eventually named "Han Yu crocodile".

Human-Crocodile War

The main period of the Hanyu crocodile's habitat was 3020 to 2540 years ago . At that time, China had entered the Bronze Age, and the Hanyu crocodile became one of the few prehistoric giants that entered the Holocene and directly confronted humans .

In the Hedang Shell Mound Site in Foshan City, Guangdong Province, which dates back to the late Neolithic period, archaeologists have discovered a series of animal remains including the Hanyu crocodile (including elephants, buffaloes, wild boars, water deer, macaques, etc.), indicating that the ecological diversity in this area was quite high at that time. Analysis of soil sediments also shows that the Pearl River Delta region at that time had a typical tropical/subtropical monsoon climate, and the overall environment was very suitable for the reproduction and growth of large crocodiles such as the Hanyu crocodile .

With the rapid increase in population and productivity, crocodiles are also multiplying and growing. Coupled with limited natural resources, the "war between humans and crocodiles" is about to break out.

The skeleton parts of Hanyu crocodile that have been discovered so far are very complete. Reference [1]

Archaeologists have found obvious marks of human-made tools on many of the Hanyu crocodile fossils unearthed so far. A specimen numbered XM12-1557 has 17 clearly visible cuts, with extremely straight edges and the deepest about 0.3 cm, arranged in different directions. This shows that this Hanyu crocodile was chopped by multiple people from multiple directions, and the final fatal wound was located above the skull. The scars on the occipital condyle of another specimen, SME1623, also show that this crocodile was beheaded with a knife after death. Its fourth vertebra was split into two and cut obliquely, and the entire cutting plane was also precise. It should have been cut off by a metal weapon from the left side of the neck at one time...

The two specimens were unearthed in the 14th to 10th century BC, when the Central Plains was in the Shang Dynasty and the Western Zhou Dynasty. Bronze ware was widely used and flowed into the Lingnan region. When humans, who were not dominant, mastered more powerful weapons, the survival challenge faced by the Hanyu crocodile became more bloody and cruel.

Cut marks on specimen XM12-1557 | Reference [1]

We are currently unable to determine the exact time point when the Han Yu crocodile became extinct, and therefore we cannot be sure whether the crocodile Han Yu offered sacrifice to was the Han Yu crocodile . If the Han Yu crocodile had not yet become extinct in the Tang Dynasty, the crocodiles Han Yu drove away at the time might have included the species named after him in later generations. Han Yu's "crocodile sacrifice" was actually just a microcosm of the conflict between ancient people and crocodiles in Lingnan. There were many recorded crocodile attacks in Lingnan throughout the dynasties, and the earliest documented record can be traced back to the Jian'an period of the Eastern Han Dynasty. But what we can be sure of is that hundreds of years after Han Yu offered sacrifice to the crocodile, there have been few records of giant crocodiles appearing in Lingnan since the Ming Dynasty. Their disappearance is directly related to the influence of human civilization.

The Baiyue ancestors in the Lingnan region mastered the slash-and-burn farming technique very early, but the extensive slash-and-burn farming brought negative impacts to the environment that could not be ignored. The original tropical evergreen broad-leaved forests and mangroves in the tidal flats shrank rapidly, and under the dual influence of climate and human beings, they turned into secondary forests and savannas. By the Tang and Song dynasties, there was little natural vegetation left in the Lingnan area. Along with it, the habitat of the giant crocodiles also disappeared.

Since the Ming Dynasty, there have been few records of giant crocodiles appearing in the Lingnan area｜Pixabay

At the same time, with the strengthening of the Central Plains' rule over Lingnan, especially the rapid increase in the number of immigrants since the Jianyan migration to the south during the Song Dynasty, the already scarce natural resources became even more scarce. Coupled with the locals' organized targeted hunting of crocodiles, the giant crocodiles gradually disappeared in Lingnan.

As a top predator, the Chinese Hanyu crocodile eventually did not escape the disaster. The destruction of its habitat was the root cause of its extinction. The battle for survival between man and crocodile ended with humans winning. The giant crocodile was never seen again, and only a piece of "Sacrifice to the Crocodile" was left.

References

Iijima, M.; Qiao, Y.; Lin, W.; Peng, Y.; Yoneda, M.; Liu, J. An intermediate crocodylian linking two extant gharials from the Bronze Age of China and its human-induced extinction. Proceedings of the Royal Society B: Biological Sciences. 2022, 289 (1970): 20220085. ISSN 1471-2954. doi:10.1098/rspb.2022.0085

Author: Alsatian Meatballs

Editor: Mai Mai

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