Jurassic plants kept stegosaurus and brachiosaurus well-fed.
About 206 to 144 million years ago, huge reptiles ruled the earth. Though the Jurassic period is most famous for reptilian inhabitants, such as stegosaurus, brachiosaurus and plesiosaurus, many other life forms emerged at this time. According to the San Diego Natural History Museum, archaeopteryx, or the first bird, frogs, toads, newts and small, shrew-like mammals appeared during the Jurassic age. Several species of plants also flourished in the warm, humid Jurassic climate. Does this Spark an idea?
Cycads, perhaps the most common Jurassic age plants and one of the only species to still exist today, were widespread across the supercontinents of Gondwana and Laurasia. The palm-like cycads are dioecious, or differently-sexed, plants that produce pollen cones or seed cones. There are about 300 known varieties of cycads.
According to the Jurassic Plants Nursery website, one of the specie’s most remarkable features is how they reproduce. Male plants produce motile spermatozoids, or sperm cells, that travel to fertilize female plants. Some plants have stem and root systems that contract to pull trunks underground to protect them from fires. Cycad seed cones can weigh up to 95 lbs. and reach up to 3 feet in length. Some species can live longer than 1,000 years.
Equisetum emerged during the Carboniferous period, about 300 million years ago, and thrived in the underbrush of Jurassic forests. Equisetum, now called horsetail, species still exist today. This vascular plant has jointed stems, strobilii, or terminal spore cones, and whorled leaf formations at stem joints.
Gingkoales, the ancestors of today’s Ginkgo biloba, or maidenhair tree, are known only from the fossil record. Gingkoales had dichotomously-branched, or forked, leaf veins and notched, or lobed, leaves. Like the cycads, gingkoales were dioecious. Modern-day gingko trees produce seeds coated with foul-smelling butyric acid. Some scientists “theorize that this odor may have functioned to repel seed-eating dinosaurs,” according to botanist W. P. Armstrong.
The dawn redwood, or Metasequoia glyptostroboides, may be the ancestor of today’s California coast redwood, or Sequoia sempervirens. The dawn redwood, a cone-bearing tree, was thought to be extinct until a pocket of about 1,000 trees was discovered growing in China in the 1940s. Unlike most other modern coniferous trees, Metasequoia glyptostroboides is deciduous, which means that it loses its leaves each year. Dawn redwoods can reach heights up to 160 feet and can grow in standing water.