Vertebrate Dispersal of Seed Plants Through Time

Abstract

■ Abstract Vertebrate dispersal of fruits and seeds is a common feature of many modern angiosperms and gymnosperms, yet the evolution and frequency of this feature in the fossil record remain unclear. Increasingly complex information suggests that (a) plants had the necessary morphological features for vertebrate dispersal by the Pennsylvanian, but possibly in the absence of clear vertebrate dispersal agents; (b) vertebrate herbivores first diversified in the Permian, and consistent dispersal relationships became possible; (c) the Mesozoic was dominated by large herbivorous dinosaurs, possible sources of diffuse, whole-plant dispersal; (d) simultaneously, several groups of small vertebrates, including lizards and, in the later Mesozoic, birds and mammals, could have established more specific vertebrate-plant associations, but supporting evidence is rudimentary; and (e) the diversification of small mammals and birds in the Tertiary established a consistent basis for organ-level interactions, allowing for the widespread occurrence of biotic dispersal in gymnosperms and angiosperms.

New Paleocene skeletons and the relationship of plesiadapiforms to crown-clade primates

“…The radiation of angiosperms in the late Cretaceous-early Tertiary, including a systematic increase in fruit and seed sizes correlated with an increasing proportion of animal-dispersed taxa (40,41), would have presented early euarchontans with ample opportunities to exploit fruit, flowers, gums, and seeds in the arboreal milieu (27). It is clear that stem primates (''Plesiadapiformes'') radiated explosively in this newly formed adaptive landscape, with even the earliest members being differentiated from insectivores by lower crowned molars with broad talonid basins and more bunodont cusps for increased exploitation of nonleafy plant resources (2) (see SI Text, Part 7,and Fig.…”

“…Thus, the sequence of characters added in early primate evolution (Fig. 5) suggests that primates acquired their suite of diagnostic features through ''diffuse coevolution'' with angiosperms through the Paleocene and that increasing fruit and seed size at this time might have been central to shaping the origin of the group (27,41). A key role for coordinated evolution of grasping and leaping features for grasp-leaping (18,36) or of grasping and visual traits for visual predation (5) is not supported.…”

Factors that shape seed mass evolution

“…Tiffney (2,8) suggested that the radiation of mammals increased the availability of dispersal agents for large seeds and, therefore, allowed plants to radiate into a wider range of seed masses than had been possible previously. This hypothesis is consistent with correlations between large-seededness and animal dispersal in presentday species (9).…”

Padrões morfológicos de diásporos de árvores e arvoretas zoocóricas no Parque Estadual de Itapuã, RS, Brasil

“…Diásporos grandes vêm sendo associados à dispersão por vetores bióticos (Hughes et al 1994;Tiffney 2004), enquanto aqueles com estruturas protetoras de modo geral restringem o consumo por aves (Janson 1983;Willson et al 1989). Como exemplos no local, os diásporos de Randia ferox e Enterolobium contortisiliquum possuem casca espessa que os torna inacessíveis às aves.…”

“…Nas angiospermas, a dispersão por aves e mamíferos tem especial relevância devido a atual abundância destes animais, que supostamente exerceram um papel decisivo na irradiação desse grupo de plantas (Tiffney 1984;Tiffney 2004). Diásporos adaptados à dispersão por aves são freqüentemente inodoros, de coloração contrastante com a vegetação, como roxa/atropurpúrea, vermelha, laranja e branca (Ridley 1930;van der Pijl 1982), algumas vezes apresentando mais de uma cor ou contrastando com estruturas acessórias ou diásporos imaturos coloridos (Ridley 1930;Stiles 1982;Willson & Thompson 1982).…”