Quantitative distribution pattern of selected spore and pollen types and carbon-isotope (δ13C) profile for carbonates (after ref. 11) from the P-Tr transition sequence in Jameson Land, East Greenland (for location, see Fig. 1). The marine macrofaunal “dead zone” embraces the interval between last appearances of the brachiopod Martinia and first appearances of the bivalve Claraia. Although the conodont element H. parvus is the first unquestionable indication of earliest Triassic age, the inception of Claraia may more accurately approximate the P-Tr boundary (11). Small, horizontal lines represent the position of palynological samples. Processed sample material is stored in the collection of the Laboratory of Palaeobotany and Palynology, Utrecht University. The recognized form-genera and other palynological categories typically reflect taxonomic diversity at generic and suprageneric levels; for botanical affinity of the types, see Table 1. Relative abundances are expressed as percentages of the total spore and pollen assemblages. Spore/pollen ratio represents counted number of spores of lycopsids, ferns, and bryophytes, divided by the total number of counted spores and pollen grains; cavate spore tetrads represent four spores. The diagram depicts the principal phases (a–e) of regional vegetation succession indicative of ecosystem collapse and initial recovery. a, decline of cordaite–pteridosperm woodland; b, proliferation of herbaceous lycopsids; c, establishment of diverse gymnosperm shrubland communities; d, renewed lycopsid proliferation; e, extinction of typical Late-Permian Subangaran gymnosperms.