deciduateadj.n.
/dᵻˈsɪdʒʊət/, /dᵻˈsɪdjʊət/, U.S. /dəˈsɪdʒ(ə)wət/ A. adj.
1. Zoology. Of a mammal: possessing a placenta which is cast off at parturition; belonging to the former group Deciduata. Now rare.
ΚΠ
1863 T. H. Huxley in Med. Times & Gaz. 30 May 553/2 The extreme cases of placentation exhibited by man and by the Pig may be termed, with Von Baer and Eschricht, from the character of the maternal placenta, ‘caducous’ and ‘non-caducous’,..or, what perhaps would be better still, the two mammals may be spoken of as ‘deciduate’ and ‘non-deciduate’.
1875 tr. E. O. Schmidt Doctr. Descent & Darwinism xi. 273 As non-deciduate mammals, the Cetacea are held to be more closely allied to the Ungulata than to the Carnivora which are deciduate.
1913 M. F. Parmelee Sci. Human Behavior xix. 379 Some of the deciduate orders stand very low among the mammals both mentally and socially.
1994 21st Biennial Symp. Animal Reprod. 13/1 These findings indicate that elevations in uterine NK cell activity occur during early pregnancy in both deciduate and non-deciduate species.
2. Zoology and Anatomy. Of a placenta: cast off at parturition; (also) characteristic or typical of a such a placenta.
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1863 T. H. Huxley in Med. Times & Gaz. 30 May 555/2 The placenta is as truly deciduate as that of a Rodent.
1868 R. Owen On Anat. Vertebr. III. xxxviii. 724 The deciduate type of lining substance.
1957 Evolution 11 419/2 The rodents and lagomorphs agree with the primates in the presence of a discoidal deciduate placenta.
2006 S. Shostak Evol. Death v. 110 Embryonic germ layers appear and form all the extraembryonic membranes, the fetal portion of the deciduate placenta, and the embryo.
B. n.
Zoology. A mammal with a deciduate placenta; a member of the former group Deciduata. Usually in plural.
ΘΚΠ
the world > animals > mammals > group Placentalia > [noun] > member of
placental1841
monodelph1842
Deciduata1866
monodelphian1873
deciduate1880
eutherian1880
placentary1890
1880 H. O. Marcy tr. G. B. Ercolani Utricular Glands Uterus 289 Among the Edentata there were some that should be classed with the deciduates.
1922 F. H. A. Marshall Physiol. of Reprod. (ed. 2) x. 408 In Deciduates the substance of the mucosa undergoes rapid growth and textural modification to form decidual tissue.
1933 H. H. Dukes Physiol. Domest. Animals xxxviii. 657 In deciduates, particularly, there is a marked development of the uterine glands during the luteal phase of the estrous cycle.
2001 N. M. Sousa et al. in R. Renaville & A. Burny Biotechnol. Animal Husbandry 180 The uterine regions shed in this way are said to be deciduous and the species with these types of placenta are called deciduates.
This entry has been updated (OED Third Edition, June 2015; most recently modified version published online March 2022).
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adj.n.1863