(a.) Having the qualities of chalk; abounding with chalk; chalky; as, cretaceous rocks and formations. See Chalk.
Example Sentences:
(1) In the investigation, the arcade-shaped prisms typical of recent mammals were first seen in material from the Cretaceous period.
(2) Fossil glycoproteins of the soluble organic matrix are present in an 80-million-year-old mollusk shell from the Late Cretaceous Period.
(3) The Masiakasaurus knopfleri, a theropod dinosaur from the Late Cretaceous period, was named after him in 2001.
(4) Species of Spirorchis arose and diversified with North America emydids following the separation of North America and Europe in the late Cretaceous or early Tertiary periods.
(5) The diversity of tetrapods increased from the Devonian to the Permian, remained roughly constant during the Mesozoic, and then began to increase in the late Cretaceous, and continued to do so during the Tertiary.
(6) We report here the discovery of two mammal teeth from the early Cretaceous of Cameroon.
(7) Consequently, the brain's geometry has changed notably since the late Cretaceous.
(8) The known range of the Primates is extended down from the middle Paleocene to the early Paleocene and late Cretaceous by a new genus and two new species from Montana, Purgatorius unio and P. ceratops.
(9) In the Late Cretaceous (80 to 65 million years ago) when the fossil record improves, mammalian enamel investigated from North American localities, are found to be prismatic; allotherian (multituberculate) and metatherian (marsupial) enamels are usually tubular, while eutherian (placental) ones are not.
(10) Spirorchinae arose later (late Cretaceous period) as a Laurasian component parasitic in the more recent pond turtles (Emydidae + Bataguridae).
(11) Dr Corwin Sullivan of the Institute of Palaeontology and Palaeoanthropology states that “It’s always great to meet a new Cretaceous tyrant, and Lythronax might just be a particularly noteworthy one.
(12) Dr Lee Margetts, another member of the Manchester team, said: "The new study clearly demonstrates the dinosaur was more than capable of strolling across the Cretaceous planes of what is now Patagonia, South America."
(13) Integral to the origin of the eutherian style of embryogenesis was the evolution during Cretaceous time of neomorphic, extraembryonic tissues (i.e., trophoblast) having physiological properties that allowed the unique combination of intimate apposition of fetal and maternal tissues and circulatory systems, along with sustained, active morphogenesis.
(14) If so, these pathways are as old in phylogenetic history as the last common ancestor of marsupial and placental mammals--dating from the late Jurassic to early Cretaceous, perhaps 145-120 million years ago.
(15) Levels of sequence divergence, as well as the age and affinities of some mainland fossil taxa, suggest that the origin of Cricosaura was associated with the tectonic evolution of the Greater Antilles in the late Cretaceous.
(16) – Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous … 'What will survive of us is love', wrote Philip Larkin.
(17) These changes suggest: (i): an expansion in the exploitation of dry fruits and seeds by mammals on the ground as well as in the trees after the terminal Cretaceous dinosaur extinction; (ii) a relation between large nuts and rodents, which appear in the late Palaeocene and radiate in the late Eocene; (iii) a relation between primates and fleshy fruits established in the early-Middle Eocene when tropical forests reached their maximum latitudinal extent; (iv) a hiatus of several million years in the vertebrate exploitation of leaves after dinosaur extinction and before the first few mammalian herbivores in the Middle Palaeocene, followed by an expansion in the late Eocene when climates cooled and more open vegetation became established.
(18) Photograph: Andy Farke In the Late Cretaceous of North America, hadrosaurs were at their peak.
(19) Like these giants from the end of the Cretaceous, Lythronax has a relatively broad skull with the orbits facing forwards.
(20) These showed that the amphiumid and dicamptodontine-rhyacotritonine nerve patterns had evolved by the Late Cretaceous, and the sirenid pattern had probably evolved by that time.