What is the Oldest Squirrel? 
In order to answer the question, “what is the oldest squirrel?” scientists have analyzed fossil records, genetic data, and the family tree of various squirrel species. They used DNA sequences from museum specimens and live animals to derive ancestral relationships. From there, they deduced lineage histories by studying fossil records and “molecular clock” analyses, which predict changes in DNA sequences over time. They compared their results to other geological evidence to determine when squirrels diverged from one another.
Douglassciurus
The fossilized skeleton of an ancient squirrel, known as the Douglassciurus jeffersoni, was discovered in present-day Oregon. The fossil squirrel’s ancestor lived some 38 million years ago, before the last ice age. Scientists believe that Douglassciurus was not the saber-tooth squirrel. Instead, all squirrel species lived during the last ice age. According to fossil records, Douglassciurus was the oldest squirrel genus and species.
The earliest squirrel fossils were found in Wyoming 36 million years ago. As sediment covered the bones, they turned into stone. Despite their age, the remains are still very impressive. Artist Hans Hoffmann crafted the first known drawing of a red squirrel, and it has become one of the most famous drawings of a prehistoric animal. Using watercolor paints and gouache, he managed to create a highly detailed image of the red squirrel.
Although the postcranial remains of this ancient squirrel are incomplete, they show characteristic features of flying squirrels. These fossils also allow scientists to calibrate the date of divergence between the clade of flying squirrels and the earliest terrestrial mammals. Moreover, they provide insights into the evolutionary history of flying squirrels, which has been thought to have evolved 31 million to 25 million years ago. The fossils of Douglassciurus reveal that the first flying squirrels were similar to modern flying squirrels.
Sciurus ingrami
Squirrels are a diverse group of rodents that are members of the genus Sciurus and allied genera of the family Sciuridae. Their distinct characteristics include long, bushy tails, erect ears, and strong hind legs. Among their many characteristics, they are nocturnal, arboreal animals that generally live in burrows.
The early history of the Sciuridae is not fully understood, and the fossil record of the family is scant. However, a fossil squirrel skeleton has been discovered in early Oligocene deposits in Wyoming, making it the oldest fossil squirrel known. This fossil has similarities to extant squirrels, such as the auditory region of the skull, and the postcranial skeleton shows similarities between extant and fossil species.
Phylogenetic analyses of the three subspecies of Sciurus revealed deep divergences in the lineages of these squirrels. Despite being confined to limited geographic ranges, they showed that a single squirrel lineage crossed Wallace’s Line. This finding was confirmed by studies on the phylogeny of endemic Sulawesi squirrels, as well as those of outgroup taxa from Sundaland.
In captivity, scientists have studied Sciurus ingrami. They have identified four basic postures and five grooming behaviors in this squirrel. They have also identified four categories for its diurnal activity. They spend more time resting during winter, feeding during autum, and mating chase of females. However, the species’ copulatory behaviour has not been studied during this period.
Douglassciurus neogrivensis
In recent years, researchers have found fossils of the earliest squirrel, Douglassciurus neogrivenis, in Wyoming. This squirrel is also the youngest known flying squirrel, but it is not a member of the Sciurinae. The fossil postcranial skeleton of this species is similar to extant tree squirrels and aplodontids.
The earliest fossil record for a squirrel is over 130 million years old. This fossil is considered a calibration point for the petaurid order and is considered the oldest rodent in the species. The fossil also gives the minimum age for the petaurid split. Researchers use this fossil to calibrate phylogenetic trees and to determine the age of phylogenetic groups.
This type of squirrel is hard to age, so observers often group them into age groups based on appearance alone. Generally, squirrels are classified into juveniles up to six months of age, subadults between six months and one year, and adults older than one year. Juveniles have more sparse fur, but their tail hair is dense and short. Body weight is a good separator of age. In the summer, the molar roots are coated with a broad opaque layer of cementum. During winter, a narrow dark band forms.
The age of flying squirrels has not been established with certainty. However, it is possible that they were around for a much longer period of time than previously thought. Various studies have suggested that flying squirrels evolved from tree squirrels at this time. In the early Miocene, the flying squirrels were divided into two subtribes. Moreover, flying squirrels today are related to modern flying squirrels, with similar skeletons.
What is an adult squirrel’s lifespan?
An adult squirrel’s lifespan is typically 6 to 10 years.
How long is a squirrel’s tail?
A squirrel’s tail is typically 10 to 15 inches long.
How much does a squirrel weigh?
A squirrel typically weighs between 1 and 1 1/2 pounds.
What do squirrels eat?
Squirrels are mostly herbivores and their diet consists of fruits nuts seeds and some insects.
What is the oldest squirrel on record?
The oldest squirrel on record was 24 years old.
Where do squirrels live?
Squirrels live in a variety of habitats including forests deserts and urban areas.
Do all squirrels hibernate?
No not all squirrels hibernate.
squirrels that live in colder climates are more likely to hibernate than those that live in warmer climates.
What is the difference between a ground squirrel and a tree squirrel?
Ground squirrels live in burrows underground while tree squirrels live in trees.
How many species of squirrel are there?
There are over 200 species of squirrel.
What are baby squirrels called?
Baby squirrels are called kittens or cubs.
How can you tell if a squirrel is male or female?
Male and female squirrels can be distinguished by their genitals.
How fast can a squirrel run?
Squirrels can run up to 20 miles per hour.
What is a squirrel’s natural predator?
A squirrel’s natural predators include birds of prey snakes and other mammals.
Do squirrels mate for life?
No squirrels do not mate for life.
What is the average litter size of a squirrel?
The average litter size of a squirrel is two to six kittens.
Jessica Watson is a PHD holder from the University of Washington. She studied behavior and interaction between squirrels and has presented her research in several wildlife conferences including TWS Annual Conference in Winnipeg.
