1. The fossil record of flowering plants is fragmentary and poorly understood as their remains are only found in later geological periods. 2. Early angiosperms first appeared in the Jurassic period based on pollen and plant fossils that showed angiosperm characteristics, but they did not become dominant until the Cretaceous period. 3. By the mid-Cretaceous, angiosperms expanded rapidly and came to dominate plant communities worldwide, replacing gymnosperms and other plant groups that previously dominated.

1. Fossil Angiosperms-
A general account
BY -YOGESH SHARMA

2. The fossil remains of true angiosperms
are found only in the later geological
periods and as a group they are more
modern than other vascular plants. The
fossil history of Angiosperms is too short
to enable us to approach a definite
conclusion. The palaeobotanical record
of this group is very fragmentary and
poorly understood.
The flowering plants are probably still in
the initial stages of their expansion and
the developmental trends are not clearly
expressed in the fossil series. Their
initial formative stages and their early
history is still hidden in the bowels of
the earth. Their geological record is
incomplete.
Fig. 20.1. Record of Angiosperms on earth.

3. According to Krishtofovich (1950) the new fossil forms are detected only when they begin to play a
significant role and not when they are either just arising or occupying a very modest position. The fossil record
consists mainly of wood and impressions of levels and leaf fragments with only sprinkling of seeds and fruits to
aid in their determination.
One of the most remarkable phenomena in biological evolutionary history is the rapidity with which the
angiosperms arose to a position of dominance in the plant world during the latter part of the Mesozoic era i.e.,
the Cretaceous period (about 200 million years ago).
According to Takhtajan (1958) the first angiosperms appeared in the early Jurassic flora or perhaps even at
the close of the Triassic, and played only an insignificant role among the then dominant ferns, Ginkgoales,
Cycadales, Bennettitales and Coniferales.
According to Core the angiosperms are relatively youthful as compared to other groups of plants, as their
fossils have not been found earlier than the Cretaceous and their period of rapid expansion came after the
period of dominance of gymnosperms and other lower plants.

4. •According to Arnold (1947) it is hypothetically assumed that the angiosperm line took shape at some
unknown time during the Mesozoic era and all the naked-seeded groups (the pteriodosperms ,the Cordaiales,
the Coniferales, the Cycadophytes, the Gnetales) and even the ferns had at times been proposed as the
possible precursors of the flowering plants.
•Although the flowering plants are so prominently displayed in the rocks of the late Cretaceous and Tertiary,
Botanist are quite ignorant about their origin and evolution. The main reason given is that we do not know
any series of fossil forms connecting the flowering plants with lower groups.
•Arber and Parkin (1907) tried to supply the missing link with the hypothetical “Hemiangiospermae” where
the fructifications were very much like the cycadeoid “flower”.This fructification was supposed to possess a
primitive perianth of spirally arranged leaves, an androecium of indefinite stamens also spirally arranged and
carpels which were open leaf-like structures with marginal megasporangia seated upon a dome-like
receptacle. Since there is no proof of the existence of such a fructification, the workable phylogenies cannot be
built upon hypothetical forms.

5. •The exact position in the geological sequence at which the angiosperms can first be supposed to have
originated or recognised is not certain. No angiosperm plant ever existed in the Paleozoic era and if there is any
reference of its existence in any literature it can be rejected outright. Either the formations were wrongly
determined or there was wrong identification of the plants.
•The oldest known plant of definite resemblance to an angiosperm is Fercula granulifera discovered by Harris
in the Rhaetic (late Triassic) rocks of Eastern Greenland. According to Arnold (1947) the leaves of this plant
were 7-15 cm. long and 6-8 cm. broad and are usually forked at about the middle. The petiole was short and the
apex acute.
•The leaf had a well-developed midrib and secondary veins which usually forked before the margin is reached.
Numerous stomata of dicot type were irregularly scattered slightly sunken in the lower surface. This leaf was
different from any other known in the older Mesozoic and according to him if it were found in the Cretaceous or
Tertiary it would have been placed among the dicots with certainty

6. •The probable Jurassic angiosperm is a piece of secondary wood, Homoxylon rajmahalense, a fossil from the
Rajmahal Hills by the Indian botanist Prof. Birbal Sahni (1932). Although its exact source is not known,
evidences show that it belonged to lower Jurassic period.
•The wood resembles to that of a gymnosperm in having no vessels, but the tracheid walls bear a mixture of
scalariform and circular pits as found in the family Winteraceae as well as the homoxylous Magnoliaceae such
as Trochodendron and Tetracentron.
•Subsequently Yarmolenko (1939) described two new species of Homoxylon – one from the Lower Jurassic
deposits of Western Tian-Shan and the other from the Lower Cretaceous deposits of the eastern slope of the
Urals. Sahni and Yarmolenko referred the species of the genus Homoxylon to the primitive vesselless
angiosperms of the type Tetracentron, Trochodendron and Winteraceae.
•The two other Indian botanists Hsu and Bose (1952) carried on further investigations and said that since in the
structure of its wood, Homoxylon resembles with Bennettitales.
•The most positive evidence of the existence of pre-Cretaceous angiosperms is pollen found in coal of Jurassic
age in Scotland (Arnold 1947). The pollen grains bear three longitudinal grooves similar to those of the genus
Nelumbo (family Nymphaeaceae).Accompanying them are also pollen grains resembling those of Castalia of the
same family Nymphaeaceae.
•According to Taklitajian (1958) also the remains of angiosperms begin to the found in Jurassic deposits being
represented only by pollengrains. They have been recorded from the Jurassic coals of Brora in Scotland.

7. •Takhtajian is of opinion that the discovery of tricolpate type of pollengrains in the Jurassic deposit, is a
positive evidence of the existence of angiosperms in the Jurassic period. According to him, since the
tricolpate type is derived from the monocolpate type, the latter must have arisen much earlier, probably at
the close of the Triassic period. The Triassic origin of the angiosperms is therefore entirely possible.
•The examples given above indicate that there were plants present during the Jurassic period which at least
resembled angiosperms and exhibited angiospermic characteristics. In fact angiosperms are first recognised
with certainty in the Jurassic, but they do not become important elements of the flora until the Cretaceous.
The decipherable history of the flowering plants (angiosperms) begin with the Lower Cretaceous.
•Some of the oldest angiosperms have been reported from the Lower Cretaceous Kome beds of Western
Greenland where they are interpreted by leaf impressions. Out of them Populus primaera is probably the
oldest leaf to be referred to a modern angiosperm genus.
•Slightly younger or of almost equal age are Potomac beds of Maryland containing the most extensive Lower
Cretaceous angiospermic plants, e.g., Ficophyllum, Quercophyllum, Juglandiphyllum, Nelumbites,
Menisdermites, Sapindopsis etc. One of the early Cretaceous flowering plants in England is represented by a
petrified wood in the Lower Greenland.
•There are about five genera of dicot woods described from this period which possess vessels and rays
typical of living angiosperms. The early Cretaceous angiosperms indicate the antiquity of some families of
the flowering plants such as Nymphaeaceae, Menispermaceae, Salicaceae, etc.

8. •The occurrence of monocots in the early Cretaceous in direct association with dicots proves that as far as the
fossil evidence is concerned the two groups monocots and dicots are of almost equal antiquity.Until the end of
the Lower Cretaceous the angiosperms were scanty and everywhere in minority, not exceeding 25% of all
species. This scanty occurrence of angiosperms until the end of the Lower Cretaceous is explained by
Takhtajian due to the conditions of their habitat.
•The Lower Cretaceous and Jurassic angiosperms lived mostly on the mountains where the conditions of their
fossilization were unfavourable.
•In the mid-Cretaceous, the constitution of the vegetation of the earth suddenly changed and the angiosperms
appeared, as though suddenly, in very large numbers and varieties and spread all over the world with
astonishing speed.
•Apart from their quick and sudden spread, all the Cretaceous angiosperms known to us belong to the present
day families and even genera and are represented by more or less primitive forms such as Magnoliaceae,
Nymphaeaceae and other related families as well as by forms which have progressed such as representatives of
Fagaceae, Moraceae, Euphorbiaceae etc., (Takhtajian).

9. •It is, therefore, clear that until the middle of the Cretaceous, angiosperms played only a subordinate role
and were present only in comparatively small number of genera and species.During the mid-Cretaceous
period they had the opportunity to spread with rapid speed and within a short time they occupied vast areas
of land. Simultaneously the old representatives of the Mesozoic era which dominated on the earth ceded
their place to the new comers. The mid-Cretaceous is therefore regarded as the beginning of a new era in the
history of world.
•Towards the end of the Cretaceous period there was a widespread volcanic activity in Peninsular India.
Preserved in the sedimentary deposits intercalated between the successive lava flows in found the earliest
Tertiary flora of India known as the Deccan Intertrappean flora.. So far about 167 megafossil texa of the
specific rank and a number of microfossils have been reported from this region.Among angiosperms, the
palms (monocots) were dominant.
•Eocene sediment containing fossil plants is the Fuller’s Earth deposit in Barmer District, Rajasthan. The
occurrence therein of such plants as Mesua and Garcinia reported by Lakhanpal and Bose and Cocos
described by Kaul indicates that during early Tertiary times, the climate of this region was moist enough to
support thick forests.
•Extensive deposits of Miocene strata in Assam and South India have yielded rich collections of petrified
woods of the members of the family Dipterocarpaceae growing in wet tropical climate. Similar plants also
grew in the Siwalik regions along the foot-hills of the Himalayas.