Methods of locomotion – Jack Raven Bushcraft
Methods of locomotion in mammals is closely related to the evolution of mammals so I’m starting this post with a very brief overview of that.
The lineage that lead to mammals diverged from reptiles about 325 million years ago. This evolutionary line is referred to as synapsids. It’s thought that the first true mammals arose some 250 million years ago and split into marsupials and placentals around 160 million years ago.
66 million years ago Earth was struck by an asteroid that wiped out not only the majority of dinosaurs but also many species of mammals. It‘s thought that larger mammals and mammals with a specialised diet went extinct whereas smaller mammals and mammals with a more diverse diet survived. Most marsupial species went extinct at this time.
It didn’t take long for those surviving mammal species to get bigger and diversify, probably in only a few hundred thousand years.
Today there are an estimated 6,000 + species of mammals.
Because mammals have evolved from the same line, they have more or less the same skeleton. That might not be immediately obvious, but essentially the bone structure is the same in all mammal species, it’s just that some of those bones are longer or shorter in some species, thicker or thinner, but they’re in the same basic order.
This is useful for us to know when it comes to tracking or trailing wildlife, especially in regards to the footprints they sometimes leave behind.
There are 3 means of locomotion within mammals, plantigrade, digitigrade and unguligrade. Knowing which is which can help us to identify which animal has made a particular track.
The earliest mammals were plantigrades. They had 5 toes on each of their four feet and walked on the entire sole of their feet. In technical terms, plantigrade locomotion means walking with the digitals (toes), metatarsals and tarsals (heel) flat on the ground.
Examples of plantigrades found in the British Isles include:
Over time digitigrades evolved from plantigrades. A digitigrade is an animal that walks on its toes so that the heal isn’t touching the ground. The name itself comes from Latin where digit means ‘finger’ and gradior means ‘walk’.
Digitigrades are often animal species that travel at a run or who can jump.
Examples of digitigrades found in the British Isles include:
- Walking birds
Unguligrades (or ungulates) also evolved from plantigrades. They are animals that walk on the very tips of their toes and include all hooved animals. They’re often big and typically herbivores.
Some species walk on the tips of two toes (even-toed ungulates), such as:
Sometimes they walk on one toe (odd-toed ungulates), such as
Technically speaking, cetaceans are ungulates but are generally excluded as they don’t have many of the characteristics shared by other ungulates.
We talk about different methods of locomotion on our Tracking & Nature Awareness course as well as on the IOL Bushcraft Competency Diploma.
You can see photos from these courses, as well as all of our others, on our Facebook page.
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