Palaeoryctidae ("ancient diggers") is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of non-specialized

eutheria Eutheria (from Greek , 'good, right' and , 'beast'; ), also called Pan-Placentalia, is the clade consisting of Placentalia, placental mammals and all therian mammals that are more closely related to placentals than to marsupials. Eutherians ...

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s from extinct order Palaeoryctida, that lived in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

and

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

from the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

to the middle

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

.Gregg F. Gunnell, Thomas Bown, Jonathan Ivan Bloch, Doug M. Boyer (2008.
"Proteutheria"
pp. 63–81 in C. M. Janis, G. F. Gunnell, and M. Uhen (eds.), "Evolution of Tertiary Mammals of North America. Volume 2: Small Mammals, Xenarthrans, and Marine Mammals." Cambridge University Press, Cambridge, U.K.

Description

From a near-complete skull of the genus '' Palaeoryctes'' found in

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

, it is known that palaeoryctids were small,

shrew Shrews ( family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to dif ...

-like

insectivore file:Common brown robberfly with prey.jpg, A Asilidae, robber fly eating a hoverfly An insectivore is a carnivore, carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the Entomophagy ...

s with an elongated snout similar to that of the leptictids. However, in contrast to the latter, little is known about palaeoryctids' postcranial anatomy (the skeleton without the skull). A 2024 study found shared cranial details between palaeoryctids and leptictids, suggesting a possible close relationship, plesiomorphic retentions, or convergent acquisitions. Where the leptictids were short-lived, the palaeoryctids seem to have been ancestors of

species. While their dental morphology still indicate a mostly insectivorous diet, it, to some extent, also relate to Eocene carnivores such as creodonts.

Taxonomy and phylogeny

History of phylogeny

The relationship between this archaic group and other insectivorous mammals is uncertain. Palaeoryctidae was originally assigned to the now-abandoned grouping

Insectivora The Order (biology), order Insectivora (from Latin ''insectum'' "insect" and ''vorare'' "to eat") is a now-abandoned biological grouping within the class of mammals. Some species have now been moved out, leaving the remaining ones in the order ...

by Sloan and Van Valen (1965), then to clade Proteutheria, and more recently to

Eutheria Eutheria (from Greek , 'good, right' and , 'beast'; ), also called Pan-Placentalia, is the clade consisting of Placentalia, placental mammals and all therian mammals that are more closely related to placentals than to marsupials. Eutherians ...

by Scott et al. (2002). Generally speaking Palaeoryctidae has been used as a

wastebasket taxon Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the purpose of classifying organisms that do not fit anywhere else. They are typically defined by e ...

for many archaic insectivorous mammals. According to a 2022 study by Bertrand et al., palaeoryctids are identified to be a basal group of placental mammals.

Taxonomy

Phylogeny

References

* *

External links

* * {{Taxonbar, from=Q2562058 Palaeoryctidae Paleocene mammals Eocene mammals Late Cretaceous first appearances Eocene extinctions Prehistoric mammal families