Cryptomanis
| Cryptomanis | ||||||||||||
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| Temporal occurrence | ||||||||||||
| outgoing Middle Eocene to Upper Eocene | ||||||||||||
| 42.9 to 37.7 million years | ||||||||||||
| Locations | ||||||||||||
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Asia ( Inner Mongolia ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Cryptomanis | ||||||||||||
| Gaudin , Emry & Pogue , 2006 | ||||||||||||
Cryptomanis is an extinct early relative of today's pangolins (Manidae), which lived in central Asia around 40 million years ago. It reached about the size of a Malay pangolin , but is only passed down through a single partially preserved skeleton without a skull. This emerged in 1928, but its real meaning was only recognized at the beginning of the 21st century. The genus was scientifically named in 2006. Cryptomanis is one of the few known fossil pangolin at all. Its skeleton structure suggests that the animal was capable of digging as well as climbing.
features
Cryptomanis is so far only known about a single skull-less skeleton. Based on the size of the thigh bone , the animal was about the size of today's Malay pangolin ( Manis javanica ). The spine and front limbs are incomplete. In addition, only a few complete individual elements of the spine are available, but in addition to isolated vertebrae, the complete series of lumbar vertebrae (7), sacral vertebrae (3) and the first five tail vertebrae were recovered. The number of lumbar vertebrae exceeds that of today's pangolins, in which there are usually five or six. Based on the existing ribs and broken ribs, the thoracic spine probably consisted of eleven vertebrae, a total of eight have survived. They all had strong bodies. In the few pieces with preserved vertebral arches , the spinous process was set significantly more obliquely backwards and markedly narrower than in Manis . The articular processes on the lumbar vertebrae showed a clear curvature towards the spinous process. On the caudal spine, of which a total of 17 individual elements have been preserved, only the anterior and middle vertebrae had extensions; those at the end of the tail were absent.
A ridge was formed on the incompletely preserved humerus , which extended along the shaft and served as an attachment point for the biceps , among other things . This deltopectoral ridge had a strong formation and was somewhat overfolded in the middle so that it overhanged at the sides. It ended in the shape of a groove or a dimple, whereby this depression served to anchor the tendon of the biceps. This groove also occurred in Patriomanis and, like this one, was at the lower end of the humeral shaft; in Manis it is variable. The head of the humerus consisted of a distinct bulge, but had lateral compressions. The cubit had a strong olecranon that was almost straight. On the spoke there was a clear bulge at the upper end of the shaft, which was also strongly developed in Patriomanis and Necromanis , but is poorly developed in Manis . The hind limbs are much better preserved than the front ones. The thigh bone measured 4 inches in length. The head was hemispherical and connected to the Great Rolling Hill by a bone ridge. The small rolling mound protruded from the upper end of the shaft. The gap between the two trochanters was also bridged by a ridge. Analogous to today's pangolins, a third trochanter (third rolling mound) appeared on the shaft. In Cryptomanis it was roughly in the middle of the shaft and thus significantly higher than in today's pangolins. The shaft was broad and flat, similar to Necromanis , but different from the more cylindrical shaft of the recent species. The tibia was almost the length of the femur at 9.3 cm. Here, unlike today's pangolins, there was also a prominent bar on the upper shaft. It wasn't fused to the fibula . Like the thigh bone, this was characterized by significant narrowing on the shaft.
In line with today's pangolins, Cryptomanis also had five-pointed hands and feet. The hand that were typical of the pangolins scaphoid and lunate bone grow into a scapholunaren element. The metacarpal bones , on the other hand, were noticeably flatter than in their recent relatives. The first phalanges had an extremely wide structure, only on the innermost ray was the first phalanx long and narrow. There was no significant enlargement of the central ray as in today's pangolins. A conspicuous characteristic on the foot was a cylindrical prehallux, a finger-like bone in front of the big toe, which is also known from the more recent species, but is rather flat there. Overall, the foot had a more graceful design than the hand with much longer and narrower toe sections, but the metatarsals were noticeably flattened. The second to fourth rays had the largest dimensions, but as in the hand the particularly large expression of the middle ray was missing. Both on the hand and on the foot the terminal phalanges showed clear fissures at the front end, which the claws received. Overall, they were triangular and long in shape.
Fossil finds
Very few fossil pangolins are known. Possibly the animals were rather rare at that time, similar to today's representatives, on the other hand the toothless snout often makes it difficult to identify such remains. The only known skull-less skeleton of Cryptomanis comes from Inner Mongolia and was discovered in 1928 during the Fifth Central Asiatic Expedition of the American Museum of Natural History . It emerged in the Shara Murun region and was most likely in the Shara-Murun Formation , which dates from the late Middle Eocene to the Upper Eocene and dates from 43 to 38 million years ago. The find region is about 100 km southwest of Eren Hot and 500 km northwest of Beijing . The range of today's Asian pangolins is at least 1000 km further south.
Paleobiology
In particular, the upper limb sections are built much more robustly than in today's pangolin species, which is expressed by the massive third trochanter and the ridge between the large and small rolling hillocks on the thigh bone and the stronger deltopectoral ridge on the humerus. Such features are typical of predominantly burrowing ( fossorial ) animals, but Cryptomanis lacked the elongated central rays on the hand and foot. Possibly the shape dug in a slightly different way than today's pangolins. However, it can also be assumed that in the course of the tribal history of the pangolins the characteristics of a fossorial way of life shifted from the upper to the lower limb sections. The long and slender hind feet evidently had a high degree of mobility and ability to grip; they could speak for a partly tree-climbing ( arboricole ) locomotion. However, in contrast to today's climbing pangolins, the tail was not designed as a prehensile tail, which is indicated by the missing appendages on the rearmost caudal vertebrae. Because of the mix of traits, Cryptomanis appears as an animal capable of both digging and climbing.
Systematics
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Internal systematics of the Pholidota according to Gaudin et al. 2009 and Gaudin 2010
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Cryptomanis is a genus of the extinct family of Patriomanidae . The Patriomanidae were set up in 1998 by Frederick S. Szalay and Friedemann Schrenk , but at that time included all known fossil pangolins. However, shows, among other eomanis that from the Middle Eocene of Messel Pit is handed down, still clearly urtümlichere features that no longer occur in the later forms including today pangolins. These include the unslit terminal phalanges on the hands and feet or the less curved articular processes on the lumbar vertebrae. Therefore, in 2003 Eomanis was relegated to a separate family, the Eomanidae . In addition to Cryptomanis , the Patriomanidae only contain Patriomanis from the Upper Eocene of North America and Necromanis from the Oligocene to Miocene of Eurasia. The position of Necromanis is somewhat uncertain, as this could also form the sister group of the Patriomanidae. The Patriomanidae and Manidae together form the superfamily of the Manoidea .
The first scientific description of Cryptomanis was in 2006 by Timothy J. Gaudin , Robert J. Emry and Brandon Pogue . It is based on the partial skeleton that was discovered in 1928 during the expedition of the American Museum of Natural History to Central Asia. This also represents the holotype (copy number AMNH 26140), it is kept in New York . The generic name Cryptomanis is made up of the Greek word κρυπτός ( kryptós "hidden", "secret") and the scientific name Manis for today's (Asian) pangolins. He alludes to the long time that the skeleton was hidden in the museum archive in terms of its meaning. It was originally addressed as a representative of the Creodonta , a group of predatory animals that are related to today's predators . The only known species is Cryptomanis gobiensis . The species name gobiensis is a reference to the find region.
Individual evidence
- ↑ a b c d e f Timothy J. Gaudin, Robert J. Emry and Brandon Pogue: A new genus and species of pangolin (Mammalia, Pholidota) from the late Eocene of Inner Mongolia, China. Journal of Vertebrate Paleontology 26, 2006, pp. 146-159
- ^ Robert J. Emry: A North American Oligocene pangolin and other additions to the Pholidota. Bulletin of the American Museum of Natural History 142, 1970, pp. 455-510
- ↑ a b c Timothy J. Gaudin: Pholidota. In: Lars Werdelin and William Joseph Sanders (eds.): Cenozoic Mammals of Africa. University of California Press, Berkeley, London, New York, 2010, pp. 599-602
- ^ A b Timothy J. Gaudin, Robert J. Emry, and John R. Wible: The Phylogeny of Living and Extinct Pangolins (Mammalia, Pholidota) and Associated Taxa: A Morphology Based Analysis. Journal of Mammal Evolution 16, 2009, pp. 235-305
- ^ Frederick S. Szalay and Friedemann Schrenk: The Middle Eocene Eurotamandua and a Darwinian phylogenetic Analysis. Kaupia 7, 1998, pp. 97-186
- ^ Gerhard Storch: Fossil Old World "edentates" (Mammalia). Senckenbergiana biologica 83 (1), 2003, pp. 51-60