Assertion: angiosperm's pollen | /r/HasProperty | rare
Facets:
value: extremely
type: DEGREE
Source sentences:
text: Northern Laurasian Province - temperate, humid, now above 60oN; Bisaccate pollen of Pinaceae, NO Classopollis (Cheirolepsis) or Ephedra-type pollen; monosulcate pollen of the cycadophytes is rare.
text: Detailed studies of palynological sequences from the Early Cretaceous using scanning electron microscopy also demonstrate that angiosperm-like pollen is extremely rare in pre-Barremian strata5,36–41 and that samples from the earliest Early Cretaceous (Berriasian) are devoid of pollen grains that can be assigned plausibly to angiosperms.