Researchers at Carleton University (Canada) say they have discovered the oldest fossil evidence of extended parental care.
If you feel your child is in danger, you protect him no matter what and what it costs. It’s natural, instinctive, but since when? The evolutionary history of this behavior remains very mysterious. The discovery of fossils on Cape Breton Island, Nova Scotia, allows us today to see a little more clearly.
We now know that about 309 million years ago the ancestors of mammals already showed special care for their offspring.
Inside a tree stump, Canadian researchers have discovered the remains of an adult specimen of the species Dendromaia unamakiensis protecting its young with its tail and one of its legs. They died – and were preserved – in this position. Details of the study were published in the journal Nature Ecology & Evolution.
“This is the oldest evidence of extended postnatal care in a vertebrate,” said Hillary Maddin, lead author of the study. The adult animal seems to hide and protect one of its cubs in a den (the cub is placed under the adult’s hind leg and surrounded by its tail). This type of behavior is common in today’s mammals. It is interesting to see this animal show such behavior so early in our evolutionary line ”.
Parental care is a very expensive strategy for the parent, who has to sacrifice energy and resources rather than using it for his own benefit. Investing so much in one offspring also deprives the parent of the opportunity to invest in other offspring.
We’re talking about protection here, but parental care also involves other forms of attention, such as nests and burrows or food storage. It is this notion of sacrifice, for the benefit of the survival of the species, which fascinates the specialists of evolution. Understanding the history of this behavior is essential if we are to truly understand our own history.
Researchers now aim to find fossil evidence of even older parental care. The business remains complicated, however, as the preservation process can evolve over time. Here the position of the fossils suggests a rapid burial with few movements after death. In other words, the arrangement of the two animals is a close approximation of their position just before their death.