a flying reptile of the extinct order Pterosauria, from the Cretaceous Period, having a wingspread of about 25 feet (8 meters).
Any of several very large, extinct flying reptiles (pterosaurs) of the genus Pteranodon of the Cretaceous Period. Pteranodon had a long pointed crest on its head, no teeth, a very short tail, and a wingspan upwards of 9 m (30 ft).
pteridine (těr’ĭ-dēn’) Any of a group of organic compounds having two fused six-member rings each containing two nitrogen atoms and four carbon atoms. One of the rings is a pyrimidine, the other a pyrazine. Pteridines include folic acid and the pigments of butterfly wings.
1. a combining form meaning “fern,” used in the formation of compound words: pteridology.
noun 1. the branch of botany dealing with ferns and related plants, as the horsetails and club mosses. noun 1. the branch of botany concerned with the study of ferns and related plants
[tuh-rid-uh-fahyt, ter-i-doh-] /təˈrɪd əˌfaɪt, ˈtɛr ɪ doʊ-/ noun 1. any plant of the division Pteridophyta, characterized by vascular tissue and differentiation into root, stem, and leaves, comprising the ferns, horsetails, and club mosses. pteridophyte /ˈtɛrɪdəʊˌfaɪt/ noun 1. (in traditional classification) any plant of the division Pteridophyta, reproducing by spores and having vascular tissue, roots, stems, […]
[tuh-rid-uh-spurm, ter-i-doh-] /təˈrɪd əˌspɜrm, ˈtɛr ɪ doʊ-/ noun 1. seed fern. pteridosperm /ˈtɛrɪdəˌspɜːm/ noun 1. any extinct seed-producing fernlike plant of the group Pteridospermae Also called seed fern