The study of Neanderthal teeth offers a unique window into the lives of our extinct human relatives. These durable biological records provide rich information about Neanderthal biology, their evolutionary journey, and the daily challenges they faced. By examining dental structures, scientists can reconstruct various aspects of their existence, from growth and development to dietary habits and even genetic connections to modern humans.
Unique Characteristics of Neanderthal Teeth
Neanderthal teeth exhibit several distinct features. One notable characteristic is taurodontism, which refers to an enlargement of the pulp cavity within the molars, accompanied by an apical displacement of the root bifurcation. This results in an extended body or stem of the root, resembling the teeth of cattle, hence the term “bull-toothed.” While this trait is rare in contemporary human populations, it appears with high frequency in Neanderthals.
Another distinguishing feature is the morphology of their anterior teeth, particularly the incisors. Neanderthals often possessed “shovel-shaped” incisors, characterized by prominent lingual marginal ridges, which give the tooth a scooped appearance. These incisors also displayed a high degree of labial convexity and well-developed lingual tubercles. Beyond these features, Neanderthal premolars sometimes showed complex occlusal morphology and an asymmetrical outline in the lower jaw.
Neanderthal molars, especially the upper first molars, frequently exhibited an expanded hypocone, a cusp on the back of the tooth. Lower molars often had an anterior fovea, a small pit or depression, distally bordered by a mid-trigonid crest, a ridge connecting the buccal and lingual cusps. Some studies suggest Neanderthal enamel tended to be thinner compared to modern humans.
Growth Patterns and Development Revealed by Teeth
The study of Neanderthal teeth offers significant insights into their growth rates and developmental timelines. Scientists examine dental growth lines, similar to tree rings, which are present both inside and on the surface of developing teeth. These striations, called perikymata, record new growth, with each mark signifying approximately six to twelve days of development. By counting these lines, researchers can estimate how long it took for a tooth to mature, providing an indication of an individual’s childhood duration.
Evidence suggests that Neanderthal children experienced a faster pace of dental development compared to modern humans. For example, studies on Neanderthal baby incisors and molars from sites like Krapina, Croatia, indicate they grew and erupted several months earlier than in human infants. This accelerated development meant their first teeth could have emerged around four months of age, with final baby teeth visible by seven months. This faster growth pattern is thought to have enabled Neanderthal infants to process more demanding supplementary foods at an earlier age, potentially offsetting the high energy costs associated with rapid brain growth.
More recent assessments suggest their tooth growth rate was at the accelerated end of the human range. This indicates that the extended, slow childhood characteristic of modern humans may be a more recent evolutionary development. The Scladina juvenile, a 100,000-year-old Belgian Neanderthal, was estimated to be around 8 years old at death despite showing developmental similarities to a 10-12 year old human.
Dietary Habits and Lifestyle Clues from Teeth
Neanderthal teeth serve as a detailed record of their diet and daily activities. Analysis of dental wear patterns, microscopic scratches on tooth surfaces, and chemical analyses of enamel and dental calculus (mineralized plaque) provide substantial evidence of their food sources. While traditionally viewed as primarily meat-eaters, studies of dental calculus have revealed a more varied diet that included widespread consumption of starchy plants, even in northern regions. This indicates that plant exploitation was a consistent part of their subsistence strategy, adapting to available resources across different environments.
Beyond food consumption, Neanderthals frequently used their teeth as tools, a practice known as “paramasticatory activities.” This can be seen in distinctive wear patterns, particularly on their anterior teeth, which show heavy abrasion from tasks like processing hides or holding objects. This non-dietary use often resulted in significant wear on incisors and canines, while molars remained less worn.
Isotopic analysis of tooth enamel provides further detail on their diet by examining stable carbon and nitrogen isotopes, which are incorporated into dental tissues from consumed foods. These analyses, alongside dental pathologies like calculus prevalence, suggest a diet that, depending on the region and available resources, included a mix of terrestrial animals and plant products. These analyses offer a comprehensive picture of Neanderthal behavioral adaptations and their interactions with their environment.
Genetic Links to Modern Human Teeth
Recent genetic research has uncovered connections between Neanderthal ancestry and dental traits observed in present-day humans. Genes inherited from Neanderthals may influence tooth size and shape in modern populations. For instance, a variant in the gene HS3ST3A1, potentially introgressed from Neanderthals, has been identified in individuals of European descent and is associated with thinner incisors, contributing to overall smaller tooth size. This suggests that Neanderthal genetic contributions extend beyond skeletal morphology to affect dental development.
The genetic mechanisms influencing dental characteristics are complex, involving multiple genome regions. Researchers have identified 18 such regions affecting tooth size and shape, with 17 of these not previously linked to dental dimensions. While some of these genes, like EDAR, affect tooth morphology in East Asian populations, Neanderthal-derived variants highlight their influence on human dental variation. These findings underscore how interbreeding between Neanderthals and ancient humans has left an enduring mark on our biological makeup, including our teeth.