A thick blanket of material, variously estimated at from 0.4 m to 1.5 m thick, would have given insulation sufficient to keep Dima frozen through the summer. The baby mammoth corpse was buried deep enough to be within the upper margins of permanently frozen ground, until it was uncovered by a bulldozer in 1977. Dima is now mounted and on display beside the famous Berezovka mammoth in the Zoology Museum in Leningrad.
Other Frozen Mammoths
At about the same time Dima was discovered (1977–78), another less complete mammoth mummy was found on a small tributary of the Khatanga River (Vereshchagin and Nikolaev 1982). It was found in 1977 by a reindeer herder, but not until the summer of 1978 could an expedition be fielded. The size of the tusks and the very large size of the animal indicate that it, like most of the other mammoth mummies, was an adult male.
Some skin remained on the head, including medial parts of the trunk and entire left ear. Two radiocarbon dates on the mammoth carcass itself were around 53,000 and 45,000 yr B.P. Two feet were also present, but most of the remainder consisted of a few scattered bones and hair. The carcass had been heavily scavenged and had decomposed. Although the animal was quite incomplete, the trunk tissue was moderately well preserved and consisted of 60% fat.
Like many Soviet mammoth fossils away from the regions of loess deposition, the Khatanga mammoth was preserved by burial in cross-bedded alluvial sands. Vereshchagin interprets these sands as indicating stream deposits. Ripple-marked sand had even been washed in between the rami of the lower jaw. Vereshchagin proposes that the animal lay in the open and was buried in a river channel.
Few other adult mammoth ears have been preserved in museum collections (young Dima’s, of course, were present), although several had been described by early explorers who saw mammoth mummies. A complete mammoth ear, well preserved, may sound like the epitome of esoterica to some, but it provides important information for those of us who try to visualize exactly what these creatures looked like and understand the implications of that appearance. For a big male proboscidian, the Khatanga mummy’s ear was quite small, only 33 cm high and 16 cm wide, slightly larger than the ear described from a mummy found in the 1700s (fig. 1.10).
This was an elderly mammoth; the third molar was worn halfway through, indicating, as Vereshchagin concludes, that the animal was about 50 years old. Fossil mammoth teeth recovered from late Pleistocene deposits in the Fairbanks area are usually in this stage of wear; apparently fifty years was a common life span for woolly mammoths.
That two of the feet, parts of the trunk, and the left ear were not eaten is curious. They are they most accessible body parts; abdominal skin on mammoths is so thick that few predators or scavengers could open it. I have observed that lions and hyenas in Africa usually go for elephant ears, trunks, and feet soon after the animal’s death. We do have one other specimen of an adult mammoth trunk tip collected in 1926 (fig. 1.11). Actually, two feet, the distal third of the trunk, and one ear of the Khatanga mammoth were missing. However, the presence of some of the vulnerable soft parts suggests that these parts were buried in cool soil not long before freeze-up in the late summer or autumn, as they probably did not stay exposed unfrozen in the open for long. Because frozen skin is rather impenetrable to scavengers, these parts may have gone through a winter exposed. The presence of considerable adipose tissue in the trunk also indicates an autumn or early winter death. But it is unlikely the animal died and was buried in winter, because sediments are relatively stationary during that time of year. It is more likely that parts of the mammoth were buried during the autumn it died and that other portions were buried during the ice breakup the next spring in sand reworked by flooded northern steams—a scenario that may also account for the scatter of bones.
Fig. 1.10. A comparison of mammoth and elephant ears. To dramatize the difference in size I have compared the Khatanga mammoth ear (Vereshchagin and Baryshnikov 1982) with that of an African elephant of similar age and sex (Sikes 1971). The Paleolithic drawing from the Gönnersdorf site in northern Germany shows a woolly mammoth with quite small ears.
Fig. 1.11. Unique trunk structure. The trunk tip of the woolly mammoth was unlike that of living elephants. (Far left) A mammoth drawn on the walls of Rouffignac Cave in France; (next right) a mammoth’s trunk tip displayed at the Zoological Museum in Leningrad (the only one in existence from an adult mammoth, to my knowledge). The trunk obtained in 1924 from a Siberian native who had cut it from a frozen mammoth carcass. Note the handlike structures around the nasal opening and also the wide “wings” on each side. I have interpreted the former as a specialized grazing structure for a low-density sward. The latter “wings” could have served to take snow to the mouth. Free water is usually unavailable in the winter, and proboscidians require large volumes of water because they eat dry winter food, have a fast gut transit time, and lose a lot of water in feces.
Assuming that this mammoth died on the floodplain some time in early autumn, lying partially underwater or on soft, wet sand, we might explain the preservation and lack of scavenging of those parts on the cold surface, like the right ear (if the head was lying on the right side). The remainder of the carcass would have been scavenged all winter. There would have been partial dismemberment by scavengers, both before freeze-up and afterward. Most of the muscle tissue would have been eaten away. During the spring, much of the remaining carcass would have been totally disarticulated and dispersed. Part of the carcass was lost, either not buried or washed farther downstream. Portions of the long bones still may have protruded for a season because they show considerable carnivore gnawing. Likewise, most of the tissue is macerated from these other long bones, again suggesting exposure for at least another summer. These long bones were, however, eventually covered by silt during later alluvial activity. No mention was made in research reports of fly pupae or gastrointestinal tract contents; these could have well been washed away during stream deposition.
In 1971 another frozen mammoth was found on the Shandrin River. This specimen had gastrointestinal tract contents but very little other soft tissue. The carcass dated within the Boutellier Interval: one radiocarbon date was about 42,000 yr B.P. and another 32,000 yr B.P. The Soviet literature portrays the Shandrin mammoth as a skeleton with an enormous mass of frozen viscera (around 300 kg) among its ribs. These gastrointestinal tract contents were originally studied and reported by N. G. Solonevich, B. A. Tikhomirov, and V. V. Ukraintseva (1977). They examined pollen and large, grossly identifiable woody plants and mosses.
This approach can be misleading. Pollen may provide an understanding of general vegetation but not necessarily record what the animal was eating. Likewise, a cursory examination of plant material exaggerates the proportion of easily identifiable specimens such as mosses and woody plant leaves. This approach misled people in the last century to incorrect conclusions about woolly mammoth diets, for they interpreted the presence of mosses and woody plants as evidence of the staple diet, and even contemporary researchers have stated that mammoths could survive eating present-day tundra vegetation (Colinvaux and West 1984; Colinvaux 1986). It is this cursory approach that causes Solonevich, Tikhomirov, and Ukraintseva to repeat those mistakes and conclude, again, that modern northern forests can serve as an analog for vegetation at the time the mammoth perished.
Percentage of pollen was averaged with that of spores, so the abstract indicated pollen from herbaceous plants constituted only 19% (spores constituted 77%). In fact, only one small sample of pollen was studied, and in that sample, grass (Poacea) was the most common, followed by sedge (Cyperaceae) and significant amounts of wormwood or sage (Artemisia) and larch (Larix). Other genera were found less often. Some woody plants were identified to species, such as cranberry (Vaccinium vitisideae) and larch (Larix dahurica), others only to genera, like willow (Salix). Woody plants, however, accounted for a small part of the gastrointestinal tract pollen and total biomass.
The plants from the stomach of this Shandrin mammoth were later studied by R. N.
Gorlova (1982). She concentrated primarily on a histological analysis of vegetative parts and seeds, concluding that the habitats in which mammoths once grazed were wet and that present-day vegetation 100 km south of the Shandrin mammoth location corresponds to the remains of vegetation found in the gastrointestinal tract; mammoths had lived in a marshy, tree-scattered tundra. Gorlova, however, finds that of the identifiable macrofossils, 80% were herbs, 15% woody plants, 1% mosses, 1% leaves of heathers, and 5% completely decomposed and unidentifiable plant material. She does not specify the grasses or sedges that were in the stomach but does rank grass at the top among Angiospermae, suggesting that grass was the most dominant group, as indeed it was in the previously mentioned study on pollen from the stomach of this same mammoth.
I suspect it is this careful identification of species of mosses and woody plants and neglect of grasses (which were not even identified to genera) that make the flora appear more analogous to modern communities. The predominance of herb in the Shandrin mummy’s gastrointestinal tract and the dominance of grasses are actually quite similar to studies of other mummies, which indicate that while there is continuity of many plant species, many Pleistocene vegetative patterns were not analogous to those dominating the north today (Sher 1974; Yurtsev 1982).
Gorlova found ripe fruits and seeds and examined the annual rings on the twigs of larch, dwarf birch, and willow, concluding that the mammoth died in the second half of summer.
Two mammalian anatomists, Yu. I. Yudichev and A. I. Averikhin (1982), also examined the frozen 300 kg monolith brought back from the site. This mass consisted mainly of gut contents, that is, vegetation, although parts of kidney, spleen, pancreas, and liver could be identified. These anatomists have an odd conclusion—that the animal died in spring from asphyxia. No reasons, however, are given for this assertion other than the mammoth died from bloating due to eating indigestible food. The validity of this assertation is uncertain, but one aspect of their point is well taken. Among herbivores, if death is not related to predation it is usually influenced by food. Moose and caribou not killed by predators usually die of starvation—they run out of digestible food and are forced to eat indigestible items. Thus, if we know enough about a species’ food tolerances, we can appraise death by starvation not only in the case of an empty gastrointestinal tract, but also, and much more commonly, when plant materials are present. Most carcasses of starved ungulates, for example, have a rumen filled with vegetation, but it is indigestible vegetation. Since we are just learning what normal food for a mammoth would be, it is difficulty to judge whether the vegetation found in the Shandrin mammoth was normal or indicative of an animal literally starving with a full belly.
The taphonomy of the Shandrin mammoth is unclear. It seems to have died in the late summer or autumn. How it was buried is not mentioned in the literature I reviewed. That most of the carcass was decomposed except for the bones and gut contents is not strange. Coarse plant material is less subject to destruction or decomposition than animal tissue. A number of taphonomic permutations can render a carcass to bones and gut, including differential scavenging on the surface or differential decomposition after burial. From reports listed here, it seems that most bones were present and that the rib cage was complete around the frozen viscera. If that is correct, it would seem the entire animal was buried after some aerial decomposition (the anatomists reported blowfly pupae cases on the outside of the viscera). However, the presence of visceral soft parts (kidney, heart, etc.) is more difficult to explain according to most models of preservation.
Perhaps the plant-filled viscera survived intact because it froze before it could be scavenged and spread apart. Certainly, if it had not frozen it would have been quickly dispersed by animals in search of the most delectable portions. Perhaps this mammoth went down on its ventral abdomen and lay on frozen ground, both cooling the viscera and inadvertently protecting the thin abdominal skin from predators. Once frozen, the fibrous, vegetation-filled mass would have protected other portions of the viscera from scavenging. The differential distribution of soft tissue and preservation of viscera after that point are unclear.
Kubiak (1982) presents an excellent review of mammoth appearances as determined from these mummies and how woolly mammoth morphology functioned as an adaptation to the cold steppe environment. He takes each part of the external anatomy, portion by portion, and discusses the relevance of each feature to life in the far north. As these are not directly related to the preservation processes, nor to the Blue Babe bison mummy, I do not review his conclusions but simply refer the reader to his paper.
The Selerikan Pony
Although virtually unknown compared to Dima, a mummified Pleistocene pony was discovered in Siberia in 1968 (Skarlato 1977). This mummy, a mature stallion, was carefully studied. Like Dima, it dates from marine isotope stage 3, the Boutillier Interval; however, an exact date is still in question. Radiocarbon dates on the carcass range from 35,000 to 39,000 yr B.P. This Selerikan pony is clearly related to the true caballine horses of Europe and central Asia, known variously as Equus caballus, E. ferus, and E. przewalskii, but all can be considered the same species. Vereshchagin argues in the Skarlato volume for a separate specific status for the northern horses but acknowledges a close similarity to caballids.
Actually, this is not the first horse mummy from Siberia. Lazarev (1977b) notes that in 1878, Bunge reported the carcass of a white horse thawed from frozen ground on the Yana River, 60 km above Kazach’ye, but that horse carcass was not saved. In 1950 the mummy of a mare with a large embryo was found on the upper course of the Indigirka River on Sana Creek when a mine tunnel was excavated; only part of this mummy was saved for study.
An interesting story is associated with the Selerikan find (Lazarev 1977b). The horse was found deep underground by drift gold miners. Two legs and a tail emerged from the ceiling of the mine, 9 m below the surface in frozen ground. The miners used the horse’s hind legs to hold cables and hang lanterns, but when the legs got in the way, they were blown out of the frozen ground with blasting powder and thrown away. Several months later, word of the find got back to Yakutsk and the Siberian Academy of Sciences sent a delegation to Selerikan to investigate. The body of the horse still remained, frozen in the ceiling. Using small blasting charges, the remainder of the horse was blown out. Later that summer, the horse’s legs and tail were found in the dump. However, the head could not be found, and examination of the neck skin showed that it had not been preserved with the carcass.
The block of earth containing the body was kept frozen and flown to the Zoological Institute in Leningrad, where a team of experts thawed it and examined the carcass. Most of the trunk and the forelegs were intact. Maceration between death and freezing had consumed much of the abdominal skin, but the thoracic contents and some of the abdominal parts still existed, although they were quite decayed by enzyme action. The gastrointestinal tract was full, indicating the horse had died an almost instantaneous death.
When a team returned the following summer to examine the stratigraphy and context of the mummy, they found part of the tunnel collapsed and full of water. There were other sections in which general stratigraphy could be studied, but the cave-in left details of the pony’s burial even more unclear than was the case for Dima. In his article about the Selerikan pony, Vereshchagin provides a number of scenarios that might account for death and burial, but he does not prefer one over another. The position of the carcass suggests that the pony was stuck in some mire. Its hind legs were pointing more or less downward, and its forelegs were more horizontal. The body, although resting on its right side, is generally angled upward, and absence of the head is consistent with this interpretation. While it was still alive, the pony would have held its head up, and after death the head would be the most likely part of the body to be chewed on and dragged away by carnivores. The lack of scavenging on the lower body indicates it was buried and inaccessible.
No fly pupae or cases were found, again showing that t
he carcass was not exposed for long to summer air. Also, fat deposits surrounding the heart and other viscera suggest it did not die in late winter, early spring, or even early summer. The pony’s sex could be determined by the presence of male genitalia and by the characteristic conformity of its pelvic girdle.
Like the Berezovka mammoth, the Selerikan pony has some bones that seem to have been broken after deposition. Its humeri are both broken in midshaft. Some of the ribs are also broken, and Vereshchagin (1977) proposes that this occurred by diagenetic processes, probably cryogenic deformation. To me these data suggest an animal deeply mired and sinking up to its neck. Predators soon killed the pony (recall its full gastrointestinal tract) and dragged away only the head and distal neck parts (fig. 1.12).
Like Dima, the Selerikan pony’s carcass lay within organically rich sediments, interlaced with segregation ice (Lazarev 1977a), indicating that the sediments were water saturated at the time of freezing. Although the circumstances of its death and subsequent preservation are uncertain, there is sufficient information to reconstruct the time of the year the pony died. Pollen from the gastrointestinal tract was studied by N. G. Solonevich, B. A. Tikhomirov, and V. V. Ukraintseva (1977) and identified as mature, suggesting a late summer death. This interpretation was supported by T. V. Yegorova (1977), who identified mature seeds in the gastrointestinal tract. Pelage length is characteristic of a full winter coat. These facts point to late autumn as the time of death. Vereshchagin (1977) notes that winter hair is lost quite late in many northern species, but I doubt winter hair would have persisted until late summer. Also, equids have both a winter pelt and a summer one, unlike extant northern ungulates.
Frozen Fauna of the Mammoth Steppe: The Story of Blue Babe Page 4