They are important as index fossils and in other palaeontological research. Some fossil foraminifera containing amino acids have been used to date sediments. Forbesiocrinus Forbesiocrinus was a crinoid with a round, stout calyx. Its rounded arms branched near the ends. The rings making up its stalk were of varying diameters.
Complete skeletons are almost unheard of.
Usually, isolated jaws or limb bones are more common, and they can easily be confused with the remains of salamanders, thus making identification difficult. The frogs of the Late Cretaceous would probably have appeared quite normal to us. Like the salamanders and lizards, they survived the extinctions that marked the end of the period. However, as climates cooled, their range became much more restricted. Fungal Spores Fungal spores are produced by fungi and have thick walls and various shapes.