Malvaceae Info (Home)
Fossil material of plants can be difficult to identify as to species, genus, or larger taxonomic unit, as usually what is found is individual parts of plants, such as wood, leaves, flowers, fruits or pollen, and these are often insufficient for identification, particularly for older material which is less closely related to modern material, and may be less well preserved. Consequently, and as fossils of one plant part often cannot be unambigiously associated with those of another plant part, palaeobotanists use form genera to classify parts of plants of uncertain taxonomic position. For fossil fruits the suffices -carpon, -carpum and -carpus are often used in generic names, indicating a similarity with the fruits of the modern genus whose name is combined with the suffix. It cannot be assumed that the fossil fruits represent a species particularly close to the modern genus; for example Craigia bronnii fruits were earlier interpreted as rutaceous or sapindaceous, and Nordenskioldia borealis and Sterculiocarpus coloradensis have been transferred to Trochodendraceae and Papaveraceae respectively.
I suspect that the genera and species of fossil malvaceous fruits listed below are far from an exhaustive coverage. Furthermore fossil fruits may be ascribed to a living genus, and this will be even harder to track down.
Banisteriaecarpum giganteum (Goeppert) Kräusel is a fossil fruit consisting of a large samara. It was originally described as an Acer, and subsequently interpreted as malpighiaceous [a]. (Banisteria L. is a name that has been formally rejected in favoir of Heteropterys Kunth.) Recent opinion interprets it as sterculiaceous, and associates it with the leaf fossils Byttneriophyllum tiliaefolium. A second species has been described under the name Banisteriaecarpum papilio Andreanszky.
Byttneria (Buettneria) perplexans Cockerell,from the Florissant Formation of Colorado is represented by nutlets with persistent 5-lobed calyxes. It has also been identified as being verbenaceous, under the name of Petraea perplexans (Cockerell) MacGinitie, and more recently has been made the type of the fossil betulaceous genus Asterocarpinus , as Asterocarpinus perplexans (Cockerell) Manchester. Carpolithes macrophyllus Cockerell may represent the same or a related species.
Cantitilia ("Kentish Lime") is a fossil genus known from seeds found in the Eocene London Clay strata of northern Kent (Isle of Sheppey and Herne Bay). On the basis of a detailed microstructural analysis Read and Chandler classify this genus as closely related to Tilia. Cantitilia differs from Tilia in having more (5) ovules in an ovary locule, and in the mature fruit being 2–3-seeded (most ovules not maturing), as opposed to the single-seeded state characteristic of Tilia.
The fruits of Cantitilia are syncarpous capsules. They are (4–)5-locular, many-ovulate, but with few maturing seeds, with axile placentation, and loculicidal dehiscence.
There are two known species (as of 1961), Cantitilia polysperma Reid and Chandler, and Cantitilia lobata Chandler. The fruits of the former are ovoid, 6½–13 mm long, 5–11½ mm wide, with seeds 4 to 5 mm long, 3 to 5½ mm wide. The fruits of the latter are deeply 5-lobed, 6 cm long by 11 mm across, with seeds about 4½ mm long and 3¾ mm broad.
Carpolithes is a catchall for fossil fruits, and species will belong to different taxa.
Carpolithes bowerbanki Reid & Chandler is recorded from the Lower Eocene of England. A similar fruit is recorded from the Late Palaeocene Almont and Beicegel floras of North Dakota. These have been interpreted as malvalean, but have more recently been reinterpreted as ranunculaceous, as Paleoactaea bowerbanki ((Reid & Chandler) Pigg & DeVore and Paleoactea nagelii Pigg & DeVore .
Christianacarpum is a form genus representing fossil fruits similar to those of the living genus Christiana,
Christianacarpum quinquelocularis, from the Eocene of France, is interpreted as belonging to a plant which belongs to the genus Christiana.
Daberocarpon is a presumed malvaceous fruit. Daberocarpon gerhardii Chitaley & Sheikh is based on a 10-locular fruit from the uppermost Cretaceous of the Deccan Intratrappean Beds of India [b]. Each locule is single-seeded.
The authors suggested an affinity with tribe Malveae. However the fruit preceeds the appearance of malvoid pollen within the pollen record, which suggests that we should look elsewhere for the true affinities.
Etheridgea subglobosa is a fossil fruit from the Late Cretaceous of Australia, which is assigned to Tiliaceae (Grewioideae? Brownlowiodeae?).
Fruits ascribed to the fossil species Firmiana yunnanensis are reported from the Miocene of Yunnan [c].
Fracastoria is a fruit fossil. It was described, and placed in Sterculiaceae, in the mid 19th century by Massalongo [d] , from specimens of large fruits from Bolca in northern Italy. Massalongo appears to have been a splitter, and I am skeptical that there are as many distinct taxa as he described. Most subsequent opinion treats Fracastoria as the fruits of a palm (e.g. [e]), though it has been treated as related to the much smaller Hightea (see below).
The described species are :-
Hightea is a fruit fossil, assigned to Malvaceae, from the Eocene of Britain. Bowerbank  described 10 species - Hightea attenuata, Hightea elliptica, Hightea elegans, Hightea fusiformis, Hightea inflata, Hightea minima, Hightea orbicularis, Hightea oviformis, Hightea turbinata and Hightea turgida.
Fruits assigned to Luehea newberryana (Knowlton) MacGinitie are found in the Early and Middle Eocene of Wyoming. These are now considered to belong to Populus cinnamonoides .
Malvacarpus is a form genus representing fossil fruits similar to those of extant mallows.
The type is Malvacarpus tertiarius Berry, from the Miocene of Argentina. The species Malvacarpus guinazui Berry is recorded from the Palaeocene or Eocene of the Rio Negro region of Argentina. The name Malvacarpus octoloculus has also been used.
Nordenskioldia is a fruit fossil once assigned to Tiliaceae, but now considered as a member of Trochodedraceae, with an extensive fossil record in time (Palaeocene to Miocene) and space (North America, Greenland, Scotland, Spitzbergen, Russia, Inner Mongolia). The leaf genus Zizyphiodes is thought to represent the same plant.
Pentaloculocarpon chitaleii Kapgate & Kapgate is a fruit fossil from the Intertrappean beds of the Deccan, which may be malvaceous. It is a pentalocular loculicidal capsule with axile placentation and single-seeded locules, of ovoid shape measuring 850µ by 1mm. The pericarp is differentiated into a outer thin epidermal zone, followed by middle multilayered parenchymatous zone consisting intercellular spaces and mucilage canals, followed by 1-2 layered compact inner zone. The seed has a membranous coat. The embryo is dicotyledonous and embedded in endosperm tissue. [f]
(This may not be validly published, as I have found no evidence of publication beyond a conference poster.).
Pteleaecarpum is a form genus representing fossil fruit mistakenly interpreted as related to those of Ptelea (Rutaceae). However Pteleaecarpum bronnii is now recognised as being the fruit of a species of Craigia (Tilieae), of which floral and foliar material is also available [g]. Pteleaecarpum europeum represents the same species . Fossil material of Craigia bronnii is known from several localities in Europe, including the Lower Oligocene of Hungary, the Lower Miocene of Bohemia, and the Upper Miocene of Germany
Sphinxia ovalis is a fossil fruit from the Londay Clay interpreted as being Dombeyoid, and most closely allied to Dombeya and Trochetia. (The name Sphinxia is also applied to a Devonian lycopsid; one or other usage of this generic name will be invalid.)
Fruit assigned to Sterculia palaeovillosa on the grounds of its siimilarity to the living Sterculia villosa is recorded from the Oligocene of Assam .
Sterculiocarpus is a form genus representing fossil fruits similar to those of living Sterculia.
The species Sterculiocarpus coloradensis Berry has been reduced to synonyny with Palaeoaster porosa (Papaveraceae) . Leaf material named Sterculia coloradensis consists of deeply three lobed leaves that don't present a papaveraceous aspect, and presumably does not represent the same taxon.
Other names which has been published are Sterculiocarpus eocenicus Berry and Sterculiocarpus sphericus Berry, from the Eocene Wilcox Fm, and Sterculiocarpus sezannelloides Berry from the Eocene Lagrange Fm. I do not know whether these represent genuine sterculioid fruits.
Sterculiocarpus etayoi is South American.
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