Paleosecuridaca Curtisii Gen. Et Sp. Nov., Securidaca-like Samaras (polygalaceae) from the Late Paleocene of North Dakota and Their Significance to the Divergence of Families within the Fabales
نویسندگان
چکیده
Paleosecuridaca curtisii Pigg, DeVore, and Wojciechowski gen. et sp. nov. (Polygalaceae) is described for anatomically preserved, nonschizocarpic, asymmetric samaras from the Late Paleocene (Tiffanian 3) Almont and Beicegel Creek floras of North Dakota. Paleosecuridaca is quite similar to the extant genus Securidaca L. (Polygalaceae) but has several distinctive features that warrant the establishment of a new genus. Fruits are 2.5– 3.6 cm long (x 1⁄4 3:0 cm, n 1⁄4 16) with a central ovoid nut 0.6–1.25 cm long (x 1⁄4 0:9 cm, n 1⁄4 26), 0.35–0.8 cm wide (x 1⁄4 0:6 cm, n 1⁄4 26), and 0.25–0.3 cm thick attached to a broad wing with a small secondary wing on its upper surface. The wing is vascularized by several veins running parallel to its long axis at the top and others in the main body of the wing arching downward and outward, with a few interreticulations occurring between the major veins. The nut contains a single, large locule with two well-developed seeds, each with a seed coat that has a prominent palisade layer like that of many extant genera of Polygalaceae. Specimens lack the broad attachment surface characteristic of Acer and instead have a short peduncle. Paleosecuridaca resembles the compressed fruit Deviacer Manchester from the Paleogene of western North America, Europe, and Asia and may be its anatomically preserved equivalent. The Late Paleocene Paleosecuridaca is the oldest-known megafossil representative of the Polygalaceae, a family now nested within the Fabales (sensu APG II) along with Leguminosae, Surianaceae, and Quillaja Molina on the basis of new molecular data. Together with the earliest record of Leguminosae from the Late Paleocene of Wyoming, these samaras provide independent evidence for an earlier divergence of these two families.
منابع مشابه
Susiea newsalemae gen. et sp. nov. (Nymphaeaceae): Euryale ‐like Seeds from the Late Paleocene Almont Flora, North Dakota, U.S.A
متن کامل
A new taeniolabidoid multituberculate (Mammalia) from the middle Puercan of the Nacimiento Formation, New Mexico, and a revision of taeniolabidoid systematics and phylogeny
Multituberculates were amongst the most abundant and taxonomically diverse mammals of the late Mesozoic and the Paleocene, reaching their zenith in diversity and body size in the Paleocene. Taeniolabidoidea, the topic of this paper, includes the largest known multituberculates, which possess highly complex cheek teeth adapted for herbivory. A new specimen from the early Paleocene (middle Puerca...
متن کاملFideliacyclus wombatiensis gen. et sp. nov. ndash; a Paleocene non-marine centric diatom from northern Canada with complex frustule architecture
Fideliacyclus wombatiensis gen. et sp. nov. – a Paleocene non-marine centric diatom from northern Canada with complex frustule architecture Peter A. Siver, Alexander P. Wolfe & Mark B. Edlund To cite this article: Peter A. Siver, Alexander P. Wolfe & Mark B. Edlund (2016): Fideliacyclus wombatiensis gen. et sp. nov. – a Paleocene non-marine centric diatom from northern Canada with complex frust...
متن کاملA Remarkable New Family of Jurassic Insects (Neuroptera) with Primitive Wing Venation and Its Phylogenetic Position in Neuropterida
BACKGROUND Lacewings (insect order Neuroptera), known in the fossil record since the Early Permian, were most diverse in the Mesozoic. A dramatic variety of forms ranged in that time from large butterfly-like Kalligrammatidae to minute two-winged Dipteromantispidae. PRINCIPAL FINDINGS We describe the intriguing new neuropteran family Parakseneuridae fam. nov. with three new genera and 15 new ...
متن کاملFruits of an “Old World” tribe (Phytocreneae; Icacinaceae) from the Paleogene of North and South America
The Phytocreneae (Icacinaceae) are a tribe of scrambling shrubs and lianas presently distributed in tropical Africa, Madagascar, and Indo-Malesia. We describe the oldest known fossils of this tribe and provide the first recognition of this group in the Neotropical fossil record based on distinctive fruit remains. Palaeophytocrene piggae sp. nov., from the late Paleocene of western North America...
متن کامل