Malvaceae Info (Home)
Fossil material of plants can be difficult to identify as to species, genus, or larger taxonomic units, 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 why 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. The suffix -xylon is often used in generic names, indicating a similarity with the wood of the modern genus whose name is combined with that suffix. It cannot be assumed that the fossil wood represents a species particularly close to the modern genus; for example Cretaceous Bombacoxylon is unlikely to be any more closely related to Bombax than to any other living bombacoid genus, and Hibiscoxylon niloticum would appear to be dombeyoid rather than malvoid.
I suspect that the genera and species of fossil malvaceous wood listed below are far from an exhaustive coverage. Furthermore material may be ascribed to a living genus (see my Sterculia Gallery), and this will be even harder to track down.
Bombacoxylon is a form genus representing fossil wood similar to that of extant bombacoids. The earliest records are from the Late Cretaceous of North America (e.g. the Campanian age Ajuga formation of Texas).
The species Bombacoxylon owenii (Carr.) Gottwald has a wide geographical and temporal range. It is recorded from the late Cretaceous or Eocene of Ethiopia [n], Middle or Upper Miocene of the Siwalik Hills of Pakistan [l], the Oligocene deposits of France [o] and Tunisia [m], the Neogene of Algeria, the Lower Miocene of Libya, the Miocene of Sardinia, and the Miocene of Bavaria [5, ad].
Bombacoxylon langstoni is recorded from the Campanian Ajuga formation of Texas .
Bombacoxylon galetti is recorded from the late Cretaceous or Eocene of Ethiopia [n].
Bombacoxylon is also recorded from the Tertiary of Burma [ag].
Chattawaya paliformis is found in the Middle Eocene Clarno Formation of Oregon. It is a wood similar to Pterospermum, but differing in having very large and irregularly shaped tile cells. [d]
Colaxylon is a form genus representing wood similar to that of extant Cola. Colaxylon coppensi is recorded from Chad.
Dombeyoxylon is a form genus representing wood similar to that of extant Dombeya. Dombeyoxylon sturanii is recorded from the Eocene of France [q]. Dombeyoxylon oweni which is recorded from the Eocene and Oligocene of Libya and Algeria, and the late Cretaceous or Eocene of Ethiopia, is a synonym of Bombacoxylon owenii. Dombeyoxylon monodii is recorded from the Tertiary of Algeria and French West Africa [p]. Dombeyoxylon jacksonensis Berry is recorded from the Eocene Fayette Fm. (The name suggests that it is also found in the Jackson Fm.)
Grewioxylon is a form genus representing fossil wood similar to that of extant Grewia. It possess tile cells . The earliest records are from the Late Cretaceous of North America (e.g. the Campanian age Ajuga formation of Texas). It is also reorded from the Eocene of Oregon [t], the Miocene of Germany [v], and the Tertiary of Burma [ag].
Grewioxylon indicum and Grewioxylon mahurzariense are found in the Intertrappean Beds of the Eocene (?) of India [s].
Grewioxylon fontanesii is found in Miocene and Pliocene sediments in Vietnam.
Grewioxylon microporosum is found in Miocene sediments in Bavaria. [5, ac,] as are Grewioxylon neumaieri and Grewioxylon ortenburgense [5, ad] and Grewioxylon auctumnalis .
Grewioxylon swedenborgii, from the Tertiary of the East Indies, has subsequently been identified as a dipterocarp (i.e. not malvaceous).
Grewinium was proposed as a substitute name for Grewioxylon Shallom non Schuster [r]. This suggests that two distinct taxa have been named Grewioxylon, and the name Grewinium was proposed to disambiguate Grewioxylon.
Heritieroxylon is a form genus representing fossil wood similar to that of extant Heritiera. Heritieroxylon keralaensis is described from the Middle Miocene of Kerala [g]. Heritieroxylon arunachalensis is described from the Mio-Pliocene of Arunachal Pradesh [k]. Heritieroxylon vietnamense is described from Pleistocene (dated at 700,000 years) deposits in Vietnam.
Heritieroxylon is also recorded from the Tertiary of Burma [ag].
Hibiscoxylon is a form genus representing fossil wood similar to that of extant Hibiscus. Hibiscoyxlon niloticum is found in Cretaceous sediments in Egypt [a]. Hibiscoxylon intertrappeum is found in intercalated sediments in the Deccan Traps (which are of Late Cretaceous and Lower Paleaocene age) . The latter bears tile cells of the Pterospermum type, and is interpreted by the authors as being close to that genus.
Hibiscoxylon niloticum is recorded from the late Cretaceous or Eocene of Ethiopia [n].
Javalinoxylon multiporosum is a fossil wood common in the Javalina Formation of the Maastrichtian (Late Cretaceous) of Texas [i]. It was described as malvalean, and apparently was most similiar to members of the traditional Malvaceae and Sterculiaceae. Javalinoxylon weberi is a fossil wood from late Campanian–early Maastrichtian Olmos Formation of Coahila [ae].
Pterospermoxylon is a form genus representing fossil wood similar to that of extant Pterospermum. It possess tile cells . It is recorded from the Pliocene of Kutch (India) [af] and also from the Miocene of India [i].
Quararibeoxylon sanctijosephii is described from Brasil [h].
Sterculinium dattai is recorded from the Miocene of Assam. .
class="text"Sterculioxylon is a form genus representing fossil wood similar to that of extant Sterculia. Sterculioxylon rhenanum is recorded from the Tertiary of Germany [w]. Sterculioxylon (Nicolia) aegyptiacum is recorded from the Tertiary of French Equatorial Africa [x]. Sterculioxylon freulonii is recorded from the Lower Eocene of Libya; it is said to approach Sterculia oblonga in characteristics. Sterrculioxylon deccanensis [u] and Sterculioxylon shahpuraensis [z] are recorded from the Intertrappean Formation (Palaeocene?) of the Deccan. Sterculioxylon pondicherriense is recorded from the Cuddalore Series of the Lower Miocene of eastern peninsular India [f]. Sterculioxylon kalagarhense is recorded from the Miocene of Uttar Pradesh [y]. Sterculioxylon varmahii is recorded from the Mio-Pliocene of Arunachal Pradesh [k]. Sterculioxylon dattai is recorded from the Tertiary of Assam [aa].
Nicolia aegyptiaca is recorded from the Senonian (Cretaceous) or Landenian (Tertiary) of Belgium [ab], and from the late Cretaceous or Eocene of Ethiopia [n].
Tilioxylon is a form genus representing fossil wood similar to that of extant Tilia. As Tilia has a long fossil record, composed of flowers and fruits (identifiable by their distinctive bracts), as well as pollen, leaves and wood, Tilia-like wood is often placed in Tilia rather than Tilioxylon; for example in the petrified forests of the Oligocene and Miocene of Lesbos.
Tilioxylon lueheaformis is recorded from the Palaeogene of England [j].
Triplochitioxylon is a form genus representing fossil wood similar to that of extant Triplochiton. It possess tile cells .
Triplochitioxylon oregonensis is recorded from the Eocene of North America [e].
A number of fossil wood types from Oligocene and Miocene of Japan were previously placed in Reevesia. These wood types are characterised by distinct ring porosity and tile cells in rays. Comparison with extant wood specimens showed that only one agreed with modern Reevesia, the remainder not agreeing with any extant malvalean genus. Terada and Suzuki [b] interpreted them as an extinct genus of Helicteroideae, most similar to the living genus Triplochiton, and the North American fossil wood Triplochitoxylon, to which they gave the name Wataria, in honour of an earlier worker on this material.
They recognise 3 species; Wataria miocenica (Watari) Terada and Suzuki, Wateria oligocenica (Suzuki) Terada and Suzuki and Wateria parvipora Terada and Suzuki.
Wateria miocenica and Wateria parvipora are also known from Korea [c, ah].
Wheeloxylon is a fossil wood from the Late Cretaceous of Coahuila [ai].
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