of marine algae: Types 1.Chlorophytes 2.Receptaculitids 67 CHLOROPHYTES 1.Chlorophytes - Green algae. to Holocene. •Cambrian close relationship between chlorophytes and land plants is suggested by the adaptation •A of some species to freshwater and moist soil. 68 RECEPTACULITIDS 2.Receptaculitids are lower Paleozoic marine fossils resembling sunflowers. by organisms of uncertain affinity. Produced as lime-secreting algae. Interpreted are found in Ordovician rocks, but they are also present in some Most Silurian and Devonian as well. 69 LAND PLANTS Land plants include: 1.Bryophytes - non-vascular plants Mosses, liverworts, and hornworts. Devonian to Holocene. 2.Tracheophytes - vascular plants Trees, ferns, and flowering plants. Silurian to Holocene 70 TRACHEOPHYTES have vascular tissues, or an internal system of tubes and vessels, that Tracheophytes transport water and nutrients from one part of the plant to another. water transport system is important, because plants generally withdraw water from A below the ground. Below the ground there is water but no light. Above the ground there is sunlight but there may not be water. The vascular system allows the plant to take advantage of both places. 71 TRACHEOPHYTES oldest unquestioned vascular plant fossils occur in Silurian rocks. The leafless plants with thin branching stems. Small, plants are called psilophytes. These bodies are present on the ends of the stems in fossils of Cooksonia. Spore Cooksonia, an early vascular plant of Late Silurian - Early Devonian. Height about 4 cm. 72 FIGURE 12-85 MAJOR ADVANCES IN LAND PLANTS Three major advances in land plant history, developing more efficient reproductive systems: 1.Seedless spore-bearing plants, appearing during Ordovician, and flourishing in Carboniferous coal swamps 2.Seed-producing, pollinating, but non-flowering plants appearing during Late Devonian (gymnosperms, such as conifers) 3.Flowering plants, appearing during Late Mesozoic (angiosperms)
Types of marine algae: 1.Chlorophytes 2.Receptaculitids 67 CHLOROPHYTES 1.Chlorophytes - Green algae. •Cambrian to Holocene. •A close relationship between chlorophytes and land plants is suggested by the adaptation of some species to freshwater and moist soil. 68 RECEPTACULITIDS 2.Receptaculitids are lower Paleozoic marine fossils resembling sunflowers. Produced by organisms of uncertain affinity. Interpreted as lime-secreting algae. Most are found in Ordovician rocks, but they are also present in some Silurian and Devonian as well. 69 LAND PLANTS Land plants include: 1.Bryophytes - non-vascular plants Mosses, liverworts, and hornworts. Devonian to Holocene. 2.Tracheophytes - vascular plants Trees, ferns, and flowering plants. Silurian to Holocene 70 TRACHEOPHYTES Tracheophytes have vascular tissues, or an internal system of tubes and vessels, that transport water and nutrients from one part of the plant to another. A water transport system is important, because plants generally withdraw water from below the ground. Below the ground there is water but no light. Above the ground there is sunlight but there may not be water. The vascular system allows the plant to take advantage of both places. 71 TRACHEOPHYTES The oldest unquestioned vascular plant fossils occur in Silurian rocks. Small, leafless plants with thin branching stems. These plants are called psilophytes. Spore bodies are present on the ends of the stems in fossils of Cooksonia. Cooksonia, an early vascular plant of Late Silurian - Early Devonian. Height about 4 cm. 72 FIGURE 12-85 MAJOR ADVANCES IN LAND PLANTS Three major advances in land plant history, developing more efficient reproductive systems: 1.Seedless spore-bearing plants, appearing during Ordovician, and flourishing in Carboniferous coal swamps 2.Seed-producing, pollinating, but non-flowering plants appearing during Late Devonian (gymnosperms, such as conifers) 3.Flowering plants, appearing during Late Mesozoic (angiosperms)
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