The Year of the 2022 Is the Second Year of the Tiger, in which the author works at the Shanghai Museum of Natural History. I remember that in the last round of the Year of the Tiger (2010), the author curated the special exhibition "Huaxia Tiger Howl", which incorporated some of the author's own research on tigers. Twelve years later, what new fruits of the author's research on tigers can be shared with you?
First of all, tigers occupy an important position in both Chinese and Western cultures. In mainland Taoist culture, the tiger is an important sacred beast, representing yin. In the founding emperor of the Tang Dynasty, the only emperor of the Tang Dynasty who believed in Taoism, the tomb of Li Yuan, the emperor of Tang Gaozu, there were two pairs of huge stone tigers as guardian god beasts.
Sacrifice of the Stone Tiger
Secondly, the tiger is the flagship species of nature conservation and a popular species in the field of scientific research.
The tiger is so fascinating that it plays a pivotal role in human thought and wisdom. In view of this, the author wants to interpret the tiger from three perspectives: science, culture and art.
The Year of the Tiger says the tiger, first talk about the tiger in science.
Tigers in science
Human research on tigers, since the rise of naturalism in the nineteenth century, covers classification, morphology, anatomy, cell biochemistry, ecological behavior, origin evolution, molecular genetics, and has not stopped.
So what is the content of research that people in science are most concerned about today? To sum up, there are two directions. The first is the evolution of tigers, and the questions to be answered are: Where did tigers come from? At what stage in the evolutionary history of this species in modern times?
The second is the germline development of geographic subspecies and geographic populations of tigers. For example, is there a difference between the popular Siberian tiger and the South China tiger, and the South China tiger and the southeast Asian and Indian tigers? Wild South China tigers have become extinct, and conservation relies entirely on captive populations, while long-term inbreeding has led to caged South China tiger populations being highly endangered. Is the South China tiger a separate subspecies? Or is it the same as the tigers of Southeast Asia and India? Therefore, the evolution of tigers and the study of tiger geographical subspecies are, in the final analysis, the basis for human beings to develop the protection and management of wild tigers and captive tigers.
Source: Unsplash
Then the scientific tiger begins with the evolution of the tiger.
The occurrence of the leopard genus and the origin of the tiger
To understand the origin of the tiger, it is necessary to understand the tiger's close relatives and the systematic relationship between the tiger and these close relatives. Tigers are taxonomically belong to the genus Leopard, which in addition to tigers includes snow leopards ( ) , jaguars ( ) , lions ( ) and leopards ( ) .
Leopard genus
Image source: Wikipedia
They share a common set of anatomical features that other cats do not have: for example, the hyoid bone is not fully ossified but is connected by a flexible tendon, which can make tigers and lions emit deafening roars. In addition, they have a narrow skull, a growing facial skull (about 50-60% of the total length of the skull), a thick snout, a small proportionate skull, and a strong sagittal crest, herringbone crest, and almost horizontal cranial basal axes.
These seemingly dull anatomical features are particularly important in studying the evolution of tigers. Because the fossils found in the history of the earth are hard tissues such as bones and teeth, and fossils are important evidence for the study of evolution. Therefore, figuring out the characteristics of tigers, leopards, and lion skulls and teeth is the basis for studying the fossil materials of tigers.
Feline phylogeny diagram
In 2006, Johnson et al. published in Science the study of the development of modern cat felines using molecular biological species. The study suggests that leopards, or leopards, are the earliest differentiated clades of the cat family, separated from the cat family basal trunk around the Late Miocene, dating back 600 to 8 million years. But this hypothesis lacks paleontological evidence to support it.
The earliest fossil that may be a leopard family so far is the Tibetan Bushi leopard found in the Zada Basin of Tibet, and paleomagnetic tests show that the strata found are about 4.42 million years old (MYA), belonging to the Late Miocene to the Early Cenozoic. The total data matrix based on morphological and genomic data shows that Brinell leopard is closely related to the living snow leopard, and is far from tiger, lion and leopard.
snow leopard
Fossils morphologically more in line with the characteristics of the genus Leopard are material from the Llithienic Stratigraphy in Letori, East Africa, dating back about 3.5 million years. Because the fossils found are so fragmented, paleontologists have difficulty identifying them to specific species. Thus, the evolutionary history of leopard genus, based on the germline development time of molecular biology and the corresponding evidence of fossil evidence, has a gap of 2 to 3 million years, which is called the Ghost lineage in evolution.
Although paleontologists have recently found earlier fossils in Europe that may belong to the genus Leopard, it is also difficult to identify species due to the fragmentation of specimens. Therefore, the true evolutionary starting point of the leopard genus may only be about 3 million years old.
Ancient Chinese Tiger
The reader can't help but ask, what is the ancestor of the tiger? Is the popular saber-toothed tiger the ancestor of the tiger?
First of all, although the saber-toothed tiger is a cat, its relationship with the tiger is even more distant than that of the tiger and the domestic cat. It represents a collective term for a large group of cats with more than a large group of canine teeth with flattened lateral teeth as the main feature. Although some taxa are similar to tigers in terms of body size (e.g., Saber-toothed tigers) or even in skulls and teeth (e.g., cats), they are not actually related to tigers.
Fear of cats
Then in the geological history, there may be a close relationship with the tiger, and the ancient Chinese tiger () counts as one.
First of all, this species was named by Zdansky in 1924 based on the Gehsell collection of Uppsala University. The specimen originated from Loc39, Henan, which produces the red clay layer of the three-toed horse skeleton. Unfortunately, there has been no accurate determination of this layer, so the age of the ancient Chinese tiger is still unclear. It is generally regarded as an early Pleistocene.
According to the description, the orthotype specimen of the ancient Chinese tiger is the skull of a young individual, with the characteristics of both a tiger and a lion, and finally, depending on its size, Zdansky believes that it is closer to the leopard. In 1967, hemmer, a Feline expert in Germany, studied the model of the orthotype specimen of the ancient Chinese tiger provided by Zdansky, and compared the living Suman tiger, East African lion and East African leopard using comparative anatomy and regression analysis, and believed that many features of the ancient Chinese tiger were close to the tiger and may be the ancestors of the tiger.
Ancient Chinese tiger orthographic specimen
In 2009, the authors asked Hemmer to help measure the model of his paper that year, and compared the skull measurements of more than 500 living leopard genera (tiger, jaguar, lion, leopard) to re-examine the taxonomic status of the ancient Chinese tiger with numerical analysis. The authors' findings suggest that in morphological metrology, the paleo-Chinese tiger is closer to a leopard than a tiger. Therefore, it is more appropriate to call the ancient Chinese leopard.
However, in the peer review of the paper, reviewer Lars Werdelin suggested that the original specimen of the ancient Chinese tiger had not been studied, and the measured data was rejected on the grounds that there was an error. Lars Werdelin is a world-renowned researcher on paleontores and has contributed greatly to hyenas, cats, and the Neogene carnivorous classification of Europe and Africa. Not only is he known for his excellent research, but he is also known for his harshness in peer review!
Lars Werdelin told the author that the ancient Chinese tiger orthographic specimen was on his desk, and he was surprised that the specimen had been copied. The model Zdansky provided to Hemmer may have been copied at Uppsala University (later transferred all of the Gerst's collection to the Swedish Museum of Natural History).
Although Lars Werdelin was harsh on the author's paper, he generously helped measure the paleo-Chinese tiger orthotype specimen. Later, the author asked another colleague to go to Lars Werdelin to take high-definition photos of the regular specimen. The final author's paper was published in the Mammal Review in the UK.
Restoration of the ancient Chinese tiger
Despite the repetition, the author's results still show that the ancient Chinese tiger is closer to the leopard. Lars Werdelin told him that there were still new specimens of the ancient Chinese tiger in the United States that had not been published in the study, and he could not wait to go to the United States to see what was the result of the author's trip to the United States? This leads to another species, more clearly the ancestor of the tiger——— the dragon tiger.
Dragon bears tiger
In 2004, Academician Qiu Zhanxiang published a monograph on the early Pleistocene mammal group in Gansu Longdan, which described a fossil of the leopard's maxilla produced from the dragon dan. Because the tooth size of this specimen is very close to that of the ancient Chinese tiger orthographic specimen, Academician Qiu classified it as an ancient Chinese tiger. In 2007, the authors went to the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences to study the fossil, as well as the fossil tiger found in other parts of the continent.
Dragon bears tiger submodel
When Lars Werdelin told the author that there was more complete material on the skull of the ancient Chinese tiger in the United States, he was both surprised and excited. In 2010 he studied the complete skull in company of Larry Martin, John Babiarz.
Dragon bears tiger positive mold
When the author first saw it, he found that it was different from the ancient Chinese tiger orthotype specimen. First of all, its "tiger" characteristics are more prominent: the nasal bone, the shape of the anterior nostrils, and the frontal bone are very similar to modern tigers, with a very thick upper jaw and developed canine teeth, and the upper and lower jaws of the raw canine teeth are also very developed. Is it the Paleo-Chinese tiger or another species that is more likely to be the direct ancestor of the tiger?
The author (Huang Ji) and the dragon bear the tiger zhengmo
With this question in mind, the authors worked on the material (BIOPI 00177) with Andrew Kitchener of the National Museum of Scotland and Per Christiansen of Aalborg University in Denmark.
Andrew Kitchener is a master of the traditional morphology of the current cat classification, Per Christiansen is good at using mathematical analysis to study the functional form of ancient meat, and has accumulated the living and fossil cat materials viewed and studied by major museums and universities in Europe, and the author and they teamed up to study.
According to the skull tooth trait matrix, the branch system trees of the dragon tiger and the early Pleistocene leopard genus and the modern leopard genus were calculated
The authors and their research team compared the ancient Chinese tiger orthodontic specimens, the maxillary of IVPP, BIOPSI 00177, 2 Eurasian jaguars (Panthera gombaszoegensis), 5 cave lions (Panthera spelaea), 14 mountain lions (Panthera atrox), and 600 modern tiger, snow leopard, jaguar, lion, leopard skulls.
Using a combination of branch systematics, geometric morphology, and numerical analysis, they found that BIOPSI 00177 was similar to the living tiger in the shape of the skull, and the numerical size was between the tiger and the jaguar, while the ancient Chinese tiger was very similar to the living leopard. Branch sequence systematic analysis showed that BIOPISI 00177 and tigers were sister groups.
Geometric morphological analysis of the shape of the skull of the dragon tiger and the modern leopard genus
BIOPSI 00177 is also closer to a tiger in terms of tooth detail features (canine tooth aspect ratio, premolar, split tooth cull ratio). In addition, the bite force of BIOPSI 00177 is also quite high. Since the discovery of the layer paleomagnetism of the IVPP maxillary material is 2.55 to 2.15 million years old, and the origin of BIOPSI 00177 is also Longdan, the two materials should be the same layer.
Thus, the age of BIOPSI 00177 is at least 2 million years old. Compared with the ancient Chinese tiger, it is more likely to be the ancestor of the living tiger. They named it a new species, the Dragon Tiger. In 2011, the authors and their research team published the study at the American Public Library Integrated PLoS One.
Restoration of the Dragon Bearer Tiger
Pleistocene Tiger
Although we have interpreted the ancient Chinese tiger and the dragon tiger, the great prosperity of the tiger is in the Pleistocene. At the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences, the author studied tiger fossils found in various parts of the mainland, including Shaanxi Lantian, Yunnan Xizhou, Guangxi Liucheng Giant Ape Cave and Beijing Zhoukoudian and Mountaintop Caves, of which the materials of Beijing Zhoukoudian and Guangxi Giant Ape Cave were published by Mr. Pei Wenzhong that year.
The early Pleistocene tiger in Lantian, Shaanxi (found with the skull of lantian ape man) is made of the front half of a skull and the front of the mandible. Both in form and size, it is no different from the modern tiger.
Specimen of the Blue Field Tiger
The material of the Yunnan Western Tiger is some sporadic teeth (canine teeth and molars), and the material of the Guangxi Liucheng Tiger is almost all split teeth. In Zhoukoudian, a famous Site of Peking people in the late Middle Pleistocene (about 350,000 years ago), a large number of tigers were also found, and Mr. Pei Wenzhong mentioned in his monograph on Zhoukoudian meat that he had found dozens of individual skulls, teeth, limb bones and even bones.
The Zhoukoudian tiger not only looks like a modern tiger, but also has a larger size. Particularly impressive was a fragmented skull that was larger in size than the largest living males of the Siberian and Indian tigers, but the skull features the females.
Zhoukoudian tiger specimen
You can imagine how big the Zhoukoudian tiger is if it is a male tiger that is one-third larger than the female! Hooijer studied the tiger in the Pleistocene Yanjinggou in Wanxian County, Sichuan, in the Collection of the Museum of Natural History in New York, USA, with intact skulls and limb bones.
Sichuan Wanxian tiger compared to modern South China tiger
Through comparison with modern Siberian tigers, Java and other tigers, it is also found that Pleistocene tigers are larger than modern tigers, and the hind limbs and bones are also thicker. By the late Pleistocene, or even the Holocene, tigers found in the Anyang Yin Ruins of the Holocene were already the same as modern tigers. In addition, in addition to the mainland, many tiger fossils have been found in the early and Middle Pleistocene strata of Java, including a skull and mandible material, which is the largest ever found. There are also fossils of tigers in Japan in the Late Pleistocene.
From the distribution areas of the fossils found, we can infer that the distribution range of the Pleistocene tiger has covered East and Southeast Asia, and has reached the peak of the tiger species in both geographical dispersal and morphology.
Laws of evolution
In a 2010 study of the dragon tiger, the authors compared tigers across the early Pleistocene to the Holocene continent using the size of the cleft teeth and the length of the mandibular dentition as numerical indicators. It was found that one of the evolutionary characteristics of tigers was increased in size, especially peaking after medium renewal.
One of the evolutionary characteristics of tigers is their increased body size
The second feature is that, in terms of morphology, from the dragon to the Pleistocene, Holocene and even modern tigers, although there are small changes in the skull, teeth, and even limb bones, the overall changes in their morphology are not particularly significant. The dragon tiger already has the characteristics of the "progressive hardware" of the modern tiger: developed canine teeth and thick snouts, developed brains. To sum up, from the origin of the tiger, through the Pleistocene to modern times, its evolutionary law is that its size continues to increase but there is little change in morphology. This interesting phenomenon shows that tigers were already successful in the first place.
bibliography
1. Barry JC (1987) Large carnivores (Canidae, Hyaenidae, Felidae) from Laetoli. In: Leakey MD, Harris JM, eds. Laetoli – a Pliocene site in Tanzania. Oxford: Clarendon Press. pp 235–258.
1–149.
2．Christiansen P (2008) Phylogeny of the great cats (Felidae: Pantherinae), and the influence of fossil taxa and missing characters. Cladistics 24: 977–992.
3.Hemmer H (1967) Where does ''Felis'' palaeosinensis Zdansky, 1924, belong in systematic terms? N Jahrb Geol Pala ̈ ontol Abh 129: 83–96
4．Hemmer H (1971) Fossil mammals of Java. II. Zur Fossilgeschichte des Tigers (Panthera tigris (L.) in Java. Koninkl Nederlandse Akad Wetenschap (Ser B) 74: 35–52
5. Hemmer H (1987) The phylogeny of the tiger. In: Tilson RL, Seal US, eds. Tigers of the World. The Biology, Biopolitics, Management, and Conservation of an Endangered Species. New Jersey: Noyes Publ. pp 28–35.
6. Hooijer DA (1947) Pleistocene remains of Panthera tigris (Linnaeus) subspecies from Wanhsien, Szechwan, China, compared with fossil and recent tigers from other localities. Am Mus Novitates 1346: 1–17.
7. Johnson WE, Eizirik E, Pscon-Slattery J, Murphy WJ, Antunes A, Teeling E, O’Brien SJ (2006) The Late Miocene radiation of modern Felidae: A genetic assessment. Science 311: 73–77.
8. Kitchener AC (1999) Tiger distribution, phenotypic variation and conservation issues. In: Seidensticker J, Christie S, Jackson P, eds. Riding the tiger. Tiger conservation in human-dominated landscapes. Cambridge: Cambridge Univ Press. pp 19–39.
9. Kitchener AC, Yamaguchi N (2010) What is a Tiger? Biogeography, morphology and taxonomy. In: Tilson RL, Nyhus P, eds. Tigers of the World. The science, politics and conservation of Panthera tigris. London: Academic Press. pp 53–86.
10. Maza k JH (黄骥2010) What is Panthera palaeosinensis? Mamm Rev 40: 90–102.
11. Maza k JH (黄骥), Christiansen P, Kitchener AC (2011) Oldest Known Pantherine Skull and Evolution of the Tiger. PLoS ONE 6(10): e25483. doi:10.1371/ journal.pone.0025483
12. Pei WC (1934) On the Carnivora from locality 1 of Choukoutien. Palaeontol Sin 8: 1–216.
13. Pocock RI (1929) Tigers. J Bombay Nat Hist Soc 33: 505–541.
14. Qiu ZX, Deng T, Wang BY (2004) Early Pleistocene fauna from Longdan, Donxiang, Gansu, China. Palaeontol Sin (NS C) 27: 1–198.
15. Werdelin L, O’Brien SJ, Johnson WE, Yamaguchi N (2010) Phylogeny and evolution of cats (Felidae). In: Macdonald DW, Loveridge AJ, eds. Biology and Conservation of Wild Felids. Oxford University Press. pp 60–82.
16. Zdansky O (1924) Jungtertia ̈ re Carnivoren Chinas. Palaeontol Sin (Being C) 2:1–149.
Scientific review: Zhang Endi, professor at East China Normal University
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