Extinct camelids reveal insights about North America's ancient savannas


Date:
June 10, 2020
Source:
University of Bristol
Summary:
A new study looking at extinct camelids -- ancestors of today's
camels and llamas -- tells the story of North America's ancient
savannas and highlights how past climatic and environmental
conditions influenced the composition of mammalian faunas.



FULL STORY ==========================================================================
A new study looking at extinct camelids -- ancestors of today's camels
and llamas -- tells the story of North America's ancient savannas and highlights how past climatic and environmental conditions influenced
the composition of mammalian faunas.


========================================================================== Although savanna habitats (treed grasslands) are only found in the
tropics today, around 18 million years ago, during the Miocene epoch,
savanna ecosystems, similar to those of modern Africa, existed in the
mid latitudes of North America. At their peak -- around 12 million years
ago -- they were comparable in their mammalian diversity to that of the Serengeti today.

The study, published in Frontiers in Earth Science, is the work of palaeobiologists at the University of Bristol and the University of
Helsinki.

It provides the first quantitative characterisation of the ecomorphology
of a group of large herbivorous ungulates (i.e. hoofed mammals) known
as artiodactyls, which includes camels and antelope, from ancient North American savannas and how they compare with their counterparts from the present-day African savannas, such as the Serengeti.

Lead author of the research, Nuria Melisa Morales Garci'a from the
University of Bristol, said: "The North American savannas housed a vast diversity of camelids. In fact, camelids actually originated and first diversified in North America where they lived for more than 40 million
years and were incredibly successful and widespread." The researchers
measured the skulls, jaws and limb bones of dozens of extinct North
American artiodactyls, including camelids, and compared them with those
living today in the Serengeti savanna of East Africa. The researchers
recorded data on body size and on aspects of the anatomy of the animals
that are linked with their ecology.

"The Serengeti mammals are very well known to research: we know how
they live, how they eat and we have all their measurements. By using
what we know about them, we can make solid inferences on how the extinct artiodactyls of North America were behaving," said Professor Christine
Janis, from the University of Bristol's School of Earth Sciences and supervising author of the study.

The analysis showed that while there was considerable overlap between the ecologies of extinct and modern species, the majority of extinct camelids
were most similar to the modern common eland, an arid-adapted antelope
with a diet of grass and leaves. This reveals important information about
the ecosystem they inhabited and suggests the North American savannas were drier than modern African savannas (a notion supported by other research).

"We also studied how these faunas were affected by the climatic changes
of the Neogene: as temperatures dropped and conditions became more
arid, these faunas became more depauperate -- lacking in number and
diversity. Camels still dominated in these faunas, but the diversity of
all ungulates took a big hit.

Our study shows how ungulate faunas responded to a particular scenario
of climate change which, now more than ever, is extremely relevant in understanding what is to come," said Morales-Garci'a.


========================================================================== Story Source: Materials provided by University_of_Bristol. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Morales-Garci'a, N.M., Sa"ila", L.K., and Janis, C.M. The Neogene
savannas of North America: a retrospective analysis on
artiodactyl faunas. Frontiers in Earth Science, 2020 DOI:
10.3389/feart.2020.0019 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200610121004.htm

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