Canadian scientists have found the fossilized remains of a previously unknown varanopidae, covering his body cub. The species, dubbed Dendromaia unamakiensis, lived on the territory of Nova Scotia 306 million years ago. Now it is the oldest known evidence of the care of offspring among vertebrates, says in an article published in Nature Ecology & Evolution.
Some animals take care of their offspring to increase its chances of survival: protect, nourish, look for them to partner or provide them with shelter. This concern is especially widespread among vertebrates, and the most resource-intensive is considered prolonged postnatal care in mammals, the cubs needed in breast feeding. About the evolutionary history of parental care science, however, not much is known.
To find out how long the animals watch over the offspring, allow minerals. As a rule, to identify evidence of parental care in the fossil record can by age and species remains tightly pressed against each other. Until recently, the oldest such find was the remains of varanopids Heleosaurus scholtzi — mammalian ancestors found in South Africa.
Now a team of paleontologists from Carleton University under the leadership of Hillary Maddin (Hillary Maddin) described a much more ancient discovery. On the island of Cape Breton in Nova Scotia they found the remains of two individuals of the previously unknown species of varanid. Animals lived 40 million years before varanopids Archaeovenatorthat were considered the most ancient representatives of this family.
The position and condition of the remains indicate that the animals were instantly buried in his own hole. Based on morphological and anatomical similarities, the absence in Scotland of the known fossils of other varanopids, as well as the characteristic posture (lower specimen is covered with the rear limbs and tail high), the researchers came to the conclusion that animals are the same species. This was confirmed by phylogenetic analysis.
The researchers concluded that caring for offspring were found among the Paleozoic synapsid much more common and appeared earlier than previously thought. Detection D. unamakiensis will help to understand how parental care affects the diversity and survival of the species. According to scientists, the temperature of the hole could cause numerical and taxonomic dominance synapsid on reptiles in the Paleozoic era.
We have already talked about various strategies for the care of animals. The fathers of marmosets help offspring grow healthier and female bonobos matchmaker adult sons. Examples of parental care are found not only among vertebrates. For example, males and females of spiders Manogea porracea and bees Ceratina nigrolabiata together to grow and protect their offspring.