More Harmful Effects of Smoking Weed While Breastfeeding. More medical studies need to be done to determine marijuanaâs effects on breast milk, but below are some of the areas studies have indicated contain risk factors.urthermore, marijuana use can diminish the abilities of a mother to take care of her newborn. The American Academy of Pediatrics advises nursing mothers not to use marijuana while breastfeeding. However, in some states medical marijuana is used to treat anxiety and other medical conditions.
We can see fossils of many other reptiles in rock of the same age and even older, but Archaeopteryx lithographica is the oldest known fossil to have feathers. We conclude that this animal is a link between reptiles and birds and that birds are descended from reptiles.ossils can be used to recognize rocks of the same or different ages. The fossils in this figure are the remains of microscopic algae. The pictures shown were made with a scanning electron microscope and have been magnified about 250 times.
Eventually, only carbon remains. The thin layer of carbon left behind can show an organismâs delicate parts, like leaves on a plant. CARBON FILMS FERN FOSSILThis carbon-film fossil of afern is more than300 million years old. TRACE FOSSILS Trace fossils show the activities of organisms. An animal makes a footprint when it steps in sand or mud. Over time the footprint is buried in layers of sediment.