Paleontology is not only guessing and estimating how old a fossil is... And it's also not only imagining how dinosaur XY may have looked like during lifetime.
Paleontology also is:
Understanding the biology, physiology, anatomy, reproduction, evolution, and whole way of life of prehistoric animals, including trophic networks, life communities etc.
The way from a biocenosis to a thanatocenosis and a taphocenosis. What happens after the death of an animal? How it is transported (allochthonous/autochthonous), what changes in chemistry lead to decay and preservation of hard and soft tissues? E.g. the principles of local self-eutrophication for phosphate-based soft-tissue preservation. How is the fossil embedded in the rock? Is a fossil spirit level preserved? What diagenetic processes happen after embedding?
Understanding prehistoric climate changes by studing e.g. isotope levels, paleo-monsoon conditions during the formation of huge continents like Pangaea or Gondwana, the influence of plate tectonics on the conveyor belts of the oceans etc.
The mathematics and physics part... Breaking down animal locomotion to equations and calculations of forces and moment arms. This helps to understand how animals of giant sizes or with a completely different locomotory musculature were able to walk and to take a look at the forces, which were exerted on the joints during locomotion/mating/standing up etc.
So you see... Paleontology uses so many different natural sciences disciplines like physics, chemistry, biology, and mathematics, that practicing it becomes a natural science itself. Can you say the same thing for history?
My list could have been much longer... There are so many sub-disciplines in paleontology that it would habe taken too long to mention them all.