(n.) Any one of three species of South American ostriches of the genera Rhea and Pterocnemia. See Rhea.
Example Sentences:
Ratite
Definition:
(a.) Of or pertaining to the Ratitae.
(n.) One of the Ratitae.
Example Sentences:
(1) In ducks and ratite birds, lymph heart myocytes more slowly but progressively differentiate a cytomorphology that does not conform in all characteristics to cardiac or skeletal muscle and even resembles in some aspects, smooth muscle.
(2) Although the phylogeny of Ratites is disputed, in particular their possible common origin with Carinates, which include most of the living birds, species of the first sub-class seem to have the same neurohypophysial hormones as those of the second.
(3) We have enzymatically amplified and sequenced approximately 400 base pairs of the mitochondrial 12S rRNA gene from bones and soft tissue remains of four species of moas as well as eight other species of ratite birds and a tinamou.
(4) Two groups of flightless ratite birds existed in New Zealand during the Pleistocene: the kiwis and the moas.
(5) These data support the theory that the ancestors of penguins were flying oceanic birds and that flightlessness in penguins has evolved independently from flightlessness in ratites.
(6) In juvenile ducks and ratites some myocytes differentiate to conductile cells, much as the conductile myocytes and myofibers of the blood heart.
(7) Osteocalcin (the 6,000 dalton Mr gamma-carboxyglutamate-containing protein of bone) has been detected in acid extracts of bones of the extinct class of New Zealand ratite birds, the moas, using a radioimmunoassay for sheep osteocalcin.
(8) This is similar to the pattern shown by ratite birds, where the decline period may be variable and facilitates hatching synchrony.
(9) Ultrastructural investigations of avian cardiac muscle, including ratite hearts, have provided great insights into the mechanisms as to how excitation leads to contraction in the heart.
(10) Alignment of the N-terminal sequence of osteocalcin from the extinct moa against the osteocalcins of the extant ostrich, rhea and emu reveals the homology amongst the ratite species is greater than the homology with the chicken osteocalcin.
(11) Ratites or paleognathid birds may have a different brain-to-metabolism association.
(12) To explain the current geographic distribution of ratites and the magnitude of the transferrin distances, it is supposed that the ancestors of these flightless birds walked across land bridges between the southern continents during Cretaceous times.
(13) These predictions seem to hold well for published data on the development of eggs of fish and ratite, precocial and altricial birds.
(14) Metallic proventricular foreign bodies are a potential source of heavy metal poisoning in ratites.
(15) A biochemical approach was used to study the evolution of ratite birds, i.e., the ostriches, rheas, cassowaries, emus, and kiwis.
(16) Quantitative immunological comparison of transferrin from ratites, tinamous, and other flying birds indicates that all the ratites and tinamous are allied phylogenetically and that they are of monophyletic origin relative to other birds.
(17) Osteocalcin the major gamma carboxyglutamic acid containing protein of vertebrate bone has been purified from the bones of a specimen of Pachyornis elephantopus, a species of the extinct class of New Zealand ratite birds, the moas.
(18) The study of the ratite conduction fibers bears out the idea of an inverse relationship between the size of the gap junctions and the input resistance of cardiac cells.
(19) The geometry of the conduction fibers of ratite hearts confirms earlier observations on birds showing that the geometry of the conduction system and its component cells is adapted to hearts of different sizes and rates of contraction so as to maintain a differential in conduction velocities between the conduction system and the working fibers.
(20) Thus, New Zealand probably was colonized twice by ancestors of ratite birds.