A new species of Acer samaras from the Miocene Yeonil Group in the Pohang Basin, Korea

Geosciences Journal (Impact Factor: 0.52). 11/2008; 12(4):331-336. DOI: 10.1007/s12303-008-0033-6

ABSTRACT Acer pohangense sp. nov. belonging to Aceraceae is described based on the six detached samaras collected from the Duho Formation of the Miocene
Yeonil Group. This species is characterized by its comparatively large-sized samara with a wing and seed, and its wide divergent
angle. The occurrence of such a large-sized samara is the first on record not only in the Korean Tertiary floras, but also
in the East Asian Tertiary floras.

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    ABSTRACT: Eleven taxa of fossil woods — two gymnosperms and nine dicotyledons — were identified from 59 specimens collected from the Lower Coal-bearing Formation of the Janggi Group at Shinjeong-ri in Donghae-myeon, Pohang City, Gyeongsangbukdo, Korea. One new taxon, Fraxinus oligocenica, was discovered and identified for the first time in the Korean Peninsula. Along with the previous study, 25 Miocene wood taxa, in total, have been described from the Lower and Upper Coal-bearing formations of the Janggi Group. A considerable number of specimens of Wataria were collected in this study. Wataria is an extinct genus of the Sterculiaceae, and the determination of its true identity is an interesting paleobotanical subject. There may be a possibility that the quantity and diversity of Wataria spp. was greater in the Korean Peninsula than in the Japanese Archipelago. Thus, we suggested that the Miocene deposits in Pohang City would be better places for elucidating the real identity of Wataria than in Japan. Coalbearing formations in which fossil woods occur intervene between the Geumgwangdong Formation and the Duho Formation in which abundant fossil leaves occur. In the combined fossil-wood and fossil-leaf data from these formations, we found a transitiontype flora situated between the well-known Aniai-type and Daijimatype floras in Japan. Key wordsMiocene-fossil woods-Janggi Basin-Pohang area-Korea
    Geosciences Journal 03/2010; 14(1):11-22. · 0.52 Impact Factor
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    ABSTRACT: A total of 16 specimens of fossil-winged fruits were found from the Middle Miocene marine deposits, Duho Formation, Pohang Basin, Korea. They were identified into two structurally different groups: 15 specimens into a winged fruit of Fraxinus, and one specimen of Liriodendron. The most samaras (13 specimens) were identified as Fraxinus oishii, which is characterized by narrowly ovate or ovate–elliptic shapes that are 2.7–3.6 cm in length and 0.7–1 cm in width (l/w ratio=3.4–4). The apexes of the Fraxinus oishii samara are round or slightly emarginated, and a seed of the samara is always located at the base, of which the general shape is narrow rhombic-ellipsoidal. The seed is 1.2–2 cm long and 0.5–0.7 cm wide. Two specimens are different from the samara of Fraxinus oishii. They have a 6.6 length/width ratio (3.3 cm long and 0.5 cm wide), and thus, are temporarily classified into the Fraxinus sp. One specimen was recognized as a winged seed of Liriodendron meisenense. The wing is broadly lanceolate to elliptic in shape, has a smooth, acute apex, and is approximately 3 cm long and 0.7 cm wide. Samaras of Fraxinus oishii and Liriodendron meisenense were early reported from the Middle Miocene deposits from North Korea, but these specimens are the first discovery in South Korea. Further study of the Duho Formation may connect flora relationships between North and South Korea.
    Acta Geologica Sinica 09/2009; 83(5):845 - 852. · 1.25 Impact Factor