When these plants and animals died they combined with mud, silt, and sand to form layers of the mixture called sediments.
(these plants and animals; died; ) (they; combined; with mud, silt, and sand; T:When these plants and animals died) (the mixture; called; sediments)
these plants and animals they the mixture
died combined called
with mud, silt, and sand T:When these plants and animals died
sediments