Saber-toothed Cats Research Articles

Coincidence or evidence: was the sabretooth cat Smilodon social?

By comparing frequencies of counted extant carnivores attracted by distress calls of prey species in African ecosystems with those of fossil records found in ‘tar seeps’ in Northern America, [Carbone et al . (2009)][1] conclude that Smilodon fatalis was social. The authors argue that the ‘

The Gaping Truth: A New Rationale for the Reconstruction of the Face of Smilodon fatalis

Smilodon fatalis is the best known saber‐toothed cat. It has often been reconstructed by artists and anatomists who presume that this animal closely resembled a modern conical‐toothed felid, with the addition of elongated canine teeth. However, saber‐toothed canines do more than affect the distance to which this animal must gape to clear these teeth to make a bite. Greater gape means that there must be an increased soft tissue mass of lip and mucosa surrounding the oral opening. These tissues would be stretched to their maximum at full gape; however when relaxed, with the mouth closed, or open to less than full gape, these features would still be of greater volume than in conical‐toothed felids. It is likely that the upper lip in Smilodon would show a greater degree of sag than is typical for modern cats. The soft tissues of the nose are not preserved in Smilodon, although past reconstructions assumed that the nasal profile is nearly vertical, as is the case in modern cats. We suggest, instead, that the nasal soft tissues in Smilodon are retracted to a degree commensurate with the retraction of the nasal bones. The lower incisor row of Smilodon is strikingly larger than in comparable‐sized modern Panthera tigris, and would therefore need to be more voluminous to stretch over such teeth It is also likely that the lower lip in Smilodon sagged; perhaps causing this felid to resemble a bloodhound more than a conical‐toothed felid.Grant Funding SourceAmerican Association of Anatomists

Comparison of hindlimb muscle attachment sites of Smilodon fatalis, Neofelis nebulosa, and Felis catus

Smilodon fatalis is the Rancho La Brea saber‐tooth cat with robust extremities and a short tail, and is believed to be an ambush predator. In this study, select pelvic, femoral, and tibial muscle attachment sites were determined for Smilodon fatalis based on osteological muscle scars and comparisons with muscle attachment site maps developed for Neofelis nebulosa (clouded leopard) and Felis catus (domesticated cat). Following careful dissection of several specimens of the cat and clouded leopard, the results showed that a comparison of the muscle attachment sites, proportional muscle weights, and muscle attachment site surface areas were remarkably similar. Comparison of Smilodon muscle scar locations and muscle scar surface areas with those of the cat and clouded leopard showed that all three species were also similar. Given these similarities, we are confident that our estimated recreation of the muscle attachment sites in Smilodon is reasonably accurate. In addition, we found that the attachment sites of the quadriceps femoris muscles in Smilodon had increased levels of rugosity compared to the clouded leopard and cat, supporting the concept that this animal may have been an ambush predator that required more robust muscles to leap at and grapple with prey.Grant Funding SourceNone

Parallels between playbacks and Pleistocene tar seeps suggest sociality in an extinct sabretooth cat,Smilodon

Inferences concerning the lives of extinct animals are difficult to obtain from the fossil record. Here we present a novel approach to the study of extinct carnivores, using a comparison between fossil records (n=3324) found in Late Pleistocene tar seeps at Rancho La Brea in North America and counts (n=4491) from playback experiments used to estimate carnivore abundance in Africa. Playbacks and tar seep deposits represent competitive, potentially dangerous encounters where multiple predators are lured by dying herbivores. Consequently, in both records predatory mammals and birds far outnumber herbivores. In playbacks, two large social species, lions, Panthera leo, and spotted hyenas, Crocuta crocuta, actively moved towards the sounds of distressed prey and made up 84 per cent of individuals attending. Small social species (jackals) were next most common and solitary species of all sizes were rare. In the La Brea record, two species dominated, the presumably social dire wolf Canis dirus (51%), and the sabretooth cat Smilodon fatalis (33%). As in the playbacks, a smaller social canid, the coyote Canis latrans, was third most common (8%), and known solitary species were rare (<4%). The predominance of Smilodon and other striking similarities between playbacks and the fossil record support the conclusion that Smilodon was social.

Cranial performance in the Komodo dragon (Varanus komodoensis) as revealed by high‐resolution 3‐D finite element analysis

The Komodo dragon (Varanus komodoensis) displays a unique hold and pull-feeding technique. Its delicate 'space-frame' skull morphology differs greatly from that apparent in most living large prey specialists and is suggestive of a high degree of optimization, wherein use of materials is minimized. Here, using high-resolution finite element modelling based on dissection and in vivo bite and pull data, we present results detailing the mechanical performance of the giant lizard's skull. Unlike most modern predators, V. komodoensis applies minimal input from the jaw muscles when butchering prey. Instead it uses series of actions controlled by postcranial muscles. A particularly interesting feature of the performance of the skull is that it reveals considerably lower overall stress when these additional extrinsic forces are added to those of the jaw adductors. This remarkable reduction in stress in response to additional force is facilitated by both internal and external bone anatomy. Functional correlations obtained from these analyses also provide a solid basis for the interpretation of feeding ecology in extinct species, including dinosaurs and sabre-tooth cats, with which V. komodoensis shares various cranial and dental characteristics.

Fossil Folklore from India: The Siwalik Hills and the Mahâbhârata

All over the world, from antiquity to the present, people have often explained fossil discoveries as proof of the historical truth of legends and myths, or used them as a basis for a new legend. Most often, large vertebrate fossils have been explained as bones and teeth of giant humans, dragons and monsters, saints and heroes. Smaller invertebrate fossils were often interpreted as sacred or curious relics based on their resemblance to familiar or sacred objects. India is no exception to this practice. Fossil ammonites (salagramas), for example, are worshipped as the disc (chakra) of the Hindu god Vishnu. The Siwalik Hills, below the Himalayas, are strewn with impressive Plio-Pleistocene vertebrate fossils. This paper suggests that the region was seen as the historical stage for the legendary battle as described in the Indian epic Mahâbhârata, during which hundreds of mighty, and sometimes gigantic, heroes, horses, and war elephants are said to have died. Their remains are seen in the fossil bones, skulls, jaws, and tusks of hippopotamuses (Hexaprotodon), proboscideans (Stegodon, Archidiskodon), four-horned giraffes (Sivatherium, Giraffokeryx), giant tortoises (Geochelone), sabre-toothed cats (Paramachairodus), camels (Camelus), and other species found on the surface of the Siwalik Hills. Moreover, thousands of ancient bronze javelins and spears are also found there after rains. These archaeological artefacts, along with the paleontological remains, appear to have influenced the setting and context of the great battle in the Indian epic.

How to build a mammalian super-predator

Questions surrounding the biology of large fossil predators that differ markedly from living forms have long intrigued palaeobiologists. Among such taxa few have excited more interest than sabertooth cats, whose distinctive hypertrophied canines are suggestive of killing behaviors and feeding ecologies that may have departed widely from those of extant carnivores. Moreover, considerable variation among sabertooth species is further suggestive of intriguing differences within the group. Behavior and ecology in another large, extinct mammalian carnivore, the Australian marsupial lion ( Thylacoleo carnifex), has also proven contentious. In this study, we assemble a wide range of cranio-dental and postcranial indices in a dataset including machairodont sabertooths, T. carnifex and an extensive sample of extant taxa in order to examine the palaeobiology of these charismatic fossil carnivores. Results of multivariate analyses point to significant relationships between behavior and overall body proportions in extant mammalian carnivores. Postcranial morphologies of two American dirk-tooth species of sabertooth ( Smilodon) depart greatly from those of living felids and group most closely with bears among living placentals. Scimitar-tooth species of Homotherium and Machairodus cluster with modern pantherine cats. The marsupial lion groups with Smilodon. If these latter two phylogenetically disparate clades do represent a specialized, robust ecomorph adapted to predation on large prey, then it is a body plan that might be effectively identified on the basis of a handful of ‘bear-like’ postcranial features in combination with a more typically ‘felid-like’ carnassialization of the cheektooth row.

Long in the tooth: evolution of sabertooth cat cranial shape

Sabertooths exhibit one of the most extreme feeding adaptations seen in mammals. The functional consequences of accommodating extremely elongate upper canine teeth are severe, resulting in a well-documented suite of cranial modifications. We used geometric morphometric methods to study the evolution of overall shape in the skulls of extant and extinct feline and machairodontine felids, as well as extinct nimravids. Trends in skull evolution were evaluated by using relative warps analysis and tested for association with body size and canine tooth length. Primitive sabertooths from all lineages exhibit cranial shapes more similar to conical-toothed cats, despite the presence of moderately developed saberteeth. More-derived forms in both nimravids and felids diverge in skull morphospace to form two distinct sabertooth types (dirk-toothed and scimitar-toothed) that differ in canine shape. Skull shape in conical-toothed cats is strongly associated with body size, but not canine length. However, within each sabertooth lineage, skull shape is significantly correlated with canine length, suggesting that gape-related demands drove the evolution of sabertooth skull morphology.

Sabre-toothed cats were weak in the jaw

Skull model shows a wimpy bite for fearsome cats.

Evidence of earliest human occurrence in Europe: the site of Pirro Nord (Southern Italy)

Some flint lithic artifacts were discovered in the fissure fillings of the well-known Pirro Nord site (Apulia, Southern Italy). The lithic industry, composed by three cores and some flakes, has been found to be associated to an Early Pleistocene vertebrate fossil assemblage. The fossil association contains a wide range of micromammals, including Allophaiomys ruffoi and Episoriculus gibberodon and large mammals including Bison degiulii and Equus altidens together with African elements as the gelada baboon Theropithecus and the saber-toothed cat Megantereon whitei. It defines the latest Villafranchian chronological unit (Pirro Nord Faunal Unit) in the Western European mammal biochronology. The lithic industry of Pirro Nord represents the oldest occurrence of the genus Homo in Europe as it is attributable to a chronological interval between 1.3 and 1.7 Ma. This supports the hypothesis that the genus Homo, with Oldowaian technology, extended its range in Europe, probably from western Asia, during the first half of the Early Pleistocene. The new discovery from Pirro Nord changes the chronology of the first arrival of hominids in Europe and offers new perspectives in the debate about the human dispersal in the Early Pleistocene.

Conservation and Climate Change: the Challenges Ahead

Climatic changes in the distant past were driven by natural causes, such as variations in the Earth’s orbit or the carbon dioxide (CO2) content of the atmosphere. Today, and even more so in the future, climatic changes have another driver as well: human activities (IPCC 1996). The natural greenhouse effect from clouds, water vapor, and CO2, primarily, is responsible for some 33◦ C of surface warming. Human use of the atmosphere to dump gaseous wastes adds to the natural greenhouse gases and is typically projected to result in a global warming of about 1.5◦–6◦ C in the next century (IPCC 2001a). This range— especially if beyond 1–2◦ C—could result in ecologically significant changes (Thomas et al., 2004), which is why climatic considerations are fundamental in the discussion of conservation strategies for the twenty-first century. The transition from extensive glaciations of the Ice Age to more hospitable landscapes of the Holocene took from 5,000 to 10,000 years, during which time the average global temperature increased 5–7◦ C and the sea level rose some 100 m. Thus, we estimate that over the last 20,000 years, the natural rates of warming on a sustained global basis are about 0.5◦–1.5◦ C/thousand years. There is, however, evidence amassing of regional, rapid (i.e., abrupt nonlinear) changes as well (e.g., Schneider 2004 provides an overview). Both the slower and more rapid changes radically influenced where species lived and their extinction rates. Climate change was a potential contributor—along with hunting and other human activities—to the extinctions of woolly mammoths, saber tooth cats, and enormous salamanders. During the last Ice Age, most of Canada was under ice. Pollen cores indicate that as the ice receded, boreal trees moved northward “chasing” the ice cap (i.e., moving with the warming temperature). But did the species within the boreal tree community shift in lock-step with the trees?

Dining in the Pleistocene—Who's on the menu?

Abstract The Camelot local fauna, a new fossil locality in southeastern South Carolina, has yielded a spectacularly abundant and well-preserved late Irvingtonian (ca. 400 ka) megafauna, including saber-toothed cat (Smilodon fatalis), wolf (Canis armbrusteri), cheetah (Miracinonyx inexpectatus), “camels” (Hemiauchenia macrocephala and Paleolama mirifica), tapir (Tapirus veroensis), deer (Odocoileus virginianus), sloth (Megalonyx jeffersoni), and horse (Equus sp.). Of particular interest is the number of well-preserved fossil teeth and the ability to decipher paleoecologies and paleodiets, especially for carnivores, by using carbon isotope compositions (δ13C) of these teeth. P. mirifica, M. jeffersoni, O. virginianus, and T. veroensis have the lowest δ13C values (−16‰ to −13‰, Vienna Peedee belemnite standard); C. armbrusteri, S. fatalis, and H. macrocephala have intermediate values (−13‰ to −8‰); and Equus sp. has the highest values (−7‰ to −1‰). High (&gt;−5‰) vs. low (≤−9‰) δ13C values for herbivores indicate local habitats dominated by warm-climate grasses vs. trees and shrubs. The high δ13C values for Equus sp. indicate the presence of grasslands, whereas the low δ13C values for the other herbivores generally indicate the presence of forests. Although few data are available for carnivores, moderate δ13C values for C. armbrusteri indicate that it preyed mainly upon forest herbivores. S. fatalis appears to have preferred marginal woodland-grassland areas.

Aspects of the functional morphology in the cranial and cervical skeleton of the sabre-toothed cat Paramachairodus ogygia (Kaup, 1832) (Felidae, Machairodontinae) from the Late Miocene of Spain: implications for the origins of the machairodont killing bite

The skull and cervical anatomy of the sabre-toothed felid Paramachairodus ogygia (Kaup, 1832) is described in this paper, with special attention paid to its functional morphology. Because of the scarcity of fossil remains, the anatomy of this felid has been very poorly known. However, the recently discovered Miocene carnivore trap of Batallones-1, near Madrid, Spain, has yielded almost complete skeletons of this animal, which is now one of the best known machairodontines. Consequently, the machairodont adaptations of this primitive sabre-toothed felid can be assessed for the first time. Some characters, such as the morphology of the mastoid area, reveal an intermediate state between that of felines and machairodontines, while others, such as the flattened upper canines and verticalized mandibular symphysis, show clear machairodont affinities. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 144, 363−377.

Relost and refound: Detection of a paleontologically, historically, cinematically(?), and environmentally important solution feature in the carbonate belt of southeastern Pennsylvania

The following article describes a recent geophysical survey whose purpose was to locate a solution cavity known as the “Port Kennedy Bone Cave” beneath Valley Forge National Historical Park, in the carbonate belt of South-eastern Pennsylvania. The authors must apologize at the outset for presenting an article that leaves out such important details as the actual site location and coordinates or north arrows on the figures. This “if-we-tell-you-we-have-to-kill-you” approach is necessary because the bone cave contains one of the most important middle Pleistocene (Irvingtonian, or ∼750,000 year-old) fossil deposits in North America. It contains plants, insects, turtles, snakes, birds, and mammals—including giant tapirs, ground sloths, sabre-tooth cats, cheetahs, bears, and mammoths. Some of these fossils were new to science when the cave was discovered by quarry workers in the late 1800s, and were studied by the most famous paleontologists of that time (e.g. Edwin Drinker Cope, Henry C. Mercer, and Charles Wh...

The last giant of Beringia: the mystery of the Bering Land Bridge

The captivating story of how geologist Dave Hopkins led the scientific world in proving the existence of the vanished land bridge that once connected Siberia to the New World during the Ice Ages. The intriguing theory of a land bridge periodically linking Siberia and Alaska during the coldest pulsations of the Ice Ages had been much debated since Jos de Acosta, a Spanish missionary working in Mexico and Peru, first proposed the idea of a connection between the continents in 1589. But proof of the land bridge - now named Beringia after eighteenth-century Danish explorer Vitus Bering - eluded scientists until an inquiring geologist named Dave Hopkins emerged from rural New England and set himself to the task of solving the mystery. Through the life story of Hopkins, The Last Giant of Beringia reveals the fascinating science detective story that at last confirmed the existence of the land bridge that served as the intercontinental migration route for such massive Ice Age beasts as woolly mammoths, steppe bison, giant stag-moose, dire wolves, short-faced bears, and saber-toothed cats - and for the first humans to enter the New World from Asia. After proving unambiguously that the land

Simulated bite marks

Though real Sabertooth cats are long extinct, anatomist Frank Mendel and his team plan to build a scale model of the head and jaws of a 700-pound Smilodon fatalis to reproduce the predator's deadly bite. They want to measure the forces necessary for the teeth to penetrate the skin, muscle, and other tissues of a recently dead herbivore, and use the data in a new computer-aided design (CAD) program they're developing. The CAD program, the Vertebrate Analyzer (VA), could do for muscle and bone what similar programs have done for bridges, buildings, and automobiles - let scientists probe the form and function of a complex object on the computer. Ultimately, it could shed light on human bone and muscle ailments, as well as the lives of long-gone exotic creatures.

Isotopic evidence of saber-tooth development, growth rate, and diet from the adult canine of Smilodon fatalis from Rancho La Brea

The large size of canines in saber-toothed cats suggests implicitly that they took longer to grow than “normal” canines. If this were the case, then juveniles may not have been able to use them for hunting. Consequently, juvenile Smilodon fatalis, for example, may have had to remain in a social group and be fed by adults longer than is the case for modern large cats. Analysis of the stable carbon and oxygen isotope ratios within the enamel of the sabertooth provides a reasonably direct method to determine development and growth. Variation in the oxygen isotope ratios during the ontogeny of a particular tooth has been reported in many animals, and has been shown to correlate with temperature variation related to seasonality. Variation in the carbon isotope ratios typically reflects differences in diet, and can be used to determine if a carnivore preferred a prey that ate predominantly C 3 or C 4 plants. This study analyzed stable carbon and oxygen ( δ 13C, δ 18O) isotope ratios from sequential, closely spaced samples of enamel carbonate obtained from upper canines of S. fatalis. A sequential change in δ 18O through canine ontogeny for two specimens (which averaged approximately −4‰) is consistent with nearly 1 year being sampled. The results suggest that the canines of S. fatalis grew about 80 mm during a 12-month period, or about 7 mm/month, and the total duration of growth for this species was about 18 months. S. fatalis apparently achieved its long canine by combining the canine development strategies of extant lions and tigers: a quick growth rate, and growth over a long time. Mean carbon isotope values of −10.1‰ and −11.3‰ suggest consumption of animals eating a C 3 diet.

Implications of the mastoid anatomy of larger extant felids for the evolution and predatory behaviour of sabretoothed cats (Mammalia, Carnivora, Felidae)

Muscle attachments in the mastoid region of the skull of extant felids are studied through dissection of two adult tigers Panthera tigris (Linnaeus, 1758) Pocock, 1930, a lion Panthera leo (Linnaeus, 1758) Pocock, 1930 and a puma Puma concolor (Linnaeus, 1771) Jardine, 1834, providing for the first time an adequate reference for the study of the evolution of that region in sabretoothed felids. Our study supports the inference by W. Akersten that the main muscles inserting in the mastoid process in sabretooths were those originating in the atlas, rather than those from the posterior neck, sternum and forelimb. Those inferences were based on the anatomy of the giant panda, Ailuropoda melanoleuca (David, 1869) Milne-Edwards, 1870, raising uncertainties about homology, which were founded, as revealed by our results. The mastoid muscle insertions in extant felids differ in important details from those described for Ailuropoda, but agree with those described for domestic cats, hyenas and dogs. The large, antero-ventrally projected mastoid process of pantherines allows a moderate implication of the m. obliquus capitis anterior in head-flexion. This contradicts the widespread notion that the function of this muscle in carnivores is to extend the atlanto-cranial joint and to flex it laterally, but supports previous inferences about the head-flexing function of atlanto-mastoid muscles in machairodontines. Sabretooth mastoid morphology implies larger and longer-fibred atlanto-mastoid muscles than in pantherines, and that most of their fibres ran inferior to the axis of rotation of the atlanto-occipital joint, emphasizing head-flexing action.

Extinction and re-evolution of similar adaptive types (ecomorphs) in Cenozoic North American ungulates and carnivores reflect van der Hammen's cycles

Numerous patterns in periodicity (e.g., climate, extinction, and sedimentary cycles) and evolutionary change (e.g., chronofaunas and coordinated stasis) have been described based on aspects of the geologic record. Recently, convergent occurrences of faunal types or "repeating faunas" have received attention, but a highly specific, iterative pattern was first reported over 40 years ago. In the late 1950s, van der Hammen described climatic/floral cycles on the order of six million years based on a succession of A, B, and C pollen community types in South America. These A-B-C cycles are also seen in the replacement pattern of particular carnivore and ungulate adaptive types in Cenozoic North America as reported by Martin in the 1980s. For example, in the last 36 million years, there were four iterations of a sabertooth cat ecomorph independently evolving, dominating the niche through an A-B-C cycle, and then going extinct. Here we show further support for the existence of these cycles in the dominance turnover in hippo and dog ecomorphs in the North American Cenozoic. Shared patterns of extinction and re-evolution of adaptive types among plants and mammals across two continents suggest a global mechanism, which appears to be climatic change. Iterative climatic cycles of various scales may form a predictive framework for understanding fundamental patterns in the geologic record, such as radiations, extinction, rates of change, convergence, and sedimentary cycles.

Dinomaze: Colossal Fossil Maze Book

Elizabeth Carpenter, 2001, Workman Publishing, New York (Soft cover $14.95) ISBN: 0-7611-1275-8. Think back to your earliest paleontological discovery. Perhaps you first encountered two-dimensional images of extinct placoderms, dinosaurs, and mammoths in treasured books. Perhaps you visited a vast museum, and stood amazed by the three-dimensional reconstructions of mysterious creatures that lived on Earth long before humans ever evolved. Or perhaps you were relieved when a quick glance over your shoulder assured you that the saber-toothed cat from the mammal hall was not stalking you from exhibit to exhibit. Cast aside your meticulous paleontological training for a few moments and think back to how it felt to meet Tyrannosaurus rex , Megaloceros , and Xiphactinus for the first time. Elizabeth Carpenter has captured the thrill of paleontology in her book “DINOMAZE: Colossal Fossil Maze Book.” Carpenter pulls animals from the depths of time and lucidly describes their most interesting evolutionary novelties. Carpenter presents the highlights of vertebrate evolution that span 415 million years through an artful collection of over 50 “anatomically correct” skeletal mazes of creatures ranging from Acanthostega to Archaeopteryx . Aimed at ages 5 and up, this book is a wonderful and challenging addition to any budding paleontologist's …