| Abstract Detail
Paleobotany Sender, Luis Miguel [1], Doyle, James [2], Upchurch, Garland [3]. Nelumbonaceous receptacles and associated leaves from the late Albian (Early Cretaceous) of Virginia and Spain. In 1994 Upchurch, Crane, and Drinnan described molds of floral receptacles from pond sediments of the Potomac Group at the late Albian Quantico locality in Virginia, associated with abundant peltate leaves of the widespread Albian leaf genus Nelumbites, which has fine actinodromous primary veins that branch and loop several times inside the margin. The inner surface of the mold bears protuberances that correspond to the carpel-bearing pits in the flat-topped receptacle of Nelumbo (Proteales). However, the fossil receptacles are much smaller than those of Nelumbo and show protuberances on both the part and counterpart, implying that the carpel-bearing surface was spherical, hemispherical, or ellipsoidal. A pit at the center of each protuberance was interpreted as a persistent style base. Better-preserved carpel-bearing molds from the latest Albian Boundary Marls Unit at Estercuel in Teruel province (NE Spain) can be interpreted more confidently. No counterparts of these molds are known, but a partial sedimentary cast in one specimen shows that the presumed basal side of the receptacle had no pits. However, protuberances at the edge of the mold are seen in side view, implying that the carpel-bearing surface was convex. The protuberances have a concave central area that clearly represents the convex apical portion of a carpel, with a central pit or protrusion that may represent a style or style scar. This area is bounded by a sharp rim formed by infilling of the gap between the carpel and the receptacle. A specimen from the coeval Huesa del Común locality may show pits from which the carpels had been shed. No Nelumbites leaves are known from either locality, but at Estercuel there are leaves compared with the putatively nymphaealean genus Aquatifolia from the late Albian Dakota Formation of Kansas, which has a cordate base, a strong medial primary vein with pinnate secondaries, and a distinctive swollen petiole. The Spanish leaves also have a cordate base and a swollen petiole, but they are more like Quantico Nelumbites in having a weakly differentiated medial primary. These observations raise the possibility that Aquatifolia was related to Nelumbo rather than Nymphaeales. This would mean that late Albian members of the nelumbonaceous line had more diverse leaf architecture than previously recognized, like the related platanaceous line, which produced both platanoid and Sapindopsis leaves.
1 - Universidad de Zaragoza, Área de Paleontología, Facultad de Ciencias (Geológicas), Zaragoza, 50009, Spain
2 - University of California Davis, Department of Evolution & Ecology, One Shields Avenue, Davis, CA, 95616, USA
3 - University of Colorado, Museum of Natural History, 1030 Broadway Street UCB 218, Boulder, CO, 80309, USA
Keywords:
Angiosperms
Cretaceous
Nelumbites
Spain
Virginia.
Presentation Type: Oral Paper
Number: PB4003
Abstract ID:399
Candidate for Awards:None |
