But they are not just pretty — when nails appeared on all fingers and toes in modern primates about 55 million years ago, they led to the development of critical functions, including finger pads that allow for sensitive touch and the ability to grasp, whether it’s a nail polish brush or remover to prepare for the next trend.
In a new study co-authored by University of Florida scientists, researchers recovered and analyzed the oldest fossil evidence of fingernails in modern primates, confirming the idea nails developed with small body size and disproving previous theories nails evolved with an increase in primate body size. More than 25 new specimens of Teilhardina brandti – an extinct primate originally described from a single lower molar — include pieces of upper teeth and ankle bones that show the mammal lived in trees. Its nails allowed the lemur-like animal to grasp onto branches and move through the trees with more agility, researchers said.
“If you take all the primates that are alive today, they’re all going to have characteristics that look the same, but unlike people, many of them live in trees,” said co-author Jonathan Bloch, an associate curator of vertebrate paleontology at the Florida Museum of Natural History on the UF campus. “By finding parts of the skeleton of this primitive primate, we are able to test whether nails were present in the common ancestor of the group that includes lemurs, monkeys, and humans — it’s direct evidence as opposed to speculation.”
Appearing in the current online edition of the American Journal of Physical Anthropology, the study provides a better understanding of the evolutionary relationships of one of the oldest known modern primates, as well as the time frame and environmental conditions that allowed for the development of nails on all fingers and toes, an exclusive feature among primates.
Specimens of T. brandti were collected over the last seven years in northwestern Wyoming’s Bighorn Basin and represent the earliest North American species from the group of euprimates, also known as “true” primates. The fossils date to the early Eocene epoch, about 55.8 million years ago, at the same time as a 200,000-year global warming event known as the Paleocene-Eocene Thermal Maximum occurred, Bloch said. Mammals evolved to be smaller during that time, when even- and odd-toed hoofed mammals, distantly related to modern deer and horses, also first appeared in the fossil record.
“The appearance of the first modern primates in North America co-occurred with the appearance of other modern mammals such as horses, and it’s all associated with a major global warming event,” said co-author Stephen Chester, a Yale University doctoral student and research associate at UF. “It in part set the stage for what we see today in terms of modern mammalian biodiversity.”
Less than 6 inches long, T. brandti was omnivorous, Bloch said. While archaic primates mostly had claws, some of the characteristics of modern primates include forward-facing eyes, an enlarged brain and nails on all digits.
“They are the smallest true nails known on record, whether living or fossil,” said first author Ken Rose, a professor in the Center for Functional Anatomy & Evolution at Johns Hopkins University School of Medicine. “That certainly doesn’t suggest nails developed with larger bodies.”
Based on the age of the fossils and analyses of Teilhardina species from other parts of the world, researchers were also able to analyze the hypothesis that mammals migrated from Asia into North America. Instead, they likely passed from Asia, through Europe and into North America on high-latitude land connections.
“This research really suggests that we are looking at something extremely close [to the species found in Europe] and that’s of great interest in itself,” Rose said. “We can show these species were extremely close morphologically in time and found in Europe and Wyoming.”
During the Paleocene-Eocene Thermal Maximum, average temperatures were about 15 degrees Fahrenheit higher than today, and the large variety of mammals found in the fossil record from that time remains a mystery to scientists.
“The finding of this animal and the concentrated effort of this period of time might be one of those things where the closer you look, the less you know,” said Gregg Gunnell, director of the Division of Fossil Primates at the Duke Lemur Center. “But any time we have the opportunity to add more morphological information to analyze the relationships of animals to answer these biogeographic questions, we can hopefully get closer and closer to an understanding of what led to this big radiation (diversification) of primates in the first place.”
Study co-authors also include Rachel Dunn of Johns Hopkins University and Doug Boyer of Brooklyn College, City University of New York. The research was supported by the National Science Foundation and Yale University.
Jon Bloch | EurekAlert!
Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter
16.08.2018 | National Science Foundation
Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
21.08.2018 | Ecology, The Environment and Conservation
21.08.2018 | Life Sciences
21.08.2018 | Power and Electrical Engineering