Atlantocarpus virginiensis E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN

Friis, Else Marie, Crane, Peter R. & Pedersen, Kaj Raunsgaard, 2020, Multiparted, Apocarpous Flowers From The Early Cretaceous Of Eastern North America And Portugal, Fossil Imprint 76 (2), pp. 279-296: 287

publication ID

http://doi.org/ 10.37520/fi.2020.023

persistent identifier

http://treatment.plazi.org/id/6435F619-7869-3A4F-FF44-D5FA80476204

treatment provided by

Diego

scientific name

Atlantocarpus virginiensis E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN
status

sp. nov.

Atlantocarpus virginiensis E.M.FRIIS, P.R.CRANE et K.R.PEDERSEN   sp. nov.

Text-fig. 5a–d View Text-fig

H o l o t y p e. Designated here. PP43780 (Puddledock sample 156; figured Text-fig. 5a–d View Text-fig ).

P l a n t F o s s i l N a m e s R e g i s t r y N u m b e r.

PFN001601 (for new species).

R e p o s i t o r y. Paleobotanical Collections, Department of Geology, Field Museum, Chicago, Illinois, USA (PP).

E t y m o l o g y. From the state of Virginia where the fossil was discovered.

T y p e l o c a l i t y. Puddledock , former Tarmac Lone Star Industries (Vulcan Materials) sand and gravel pit, located south of Richmond and east of the Appomattox River in Prince George County, Virginia, USA (37° 15′ 52″ N, 77°22′ 10″ W) GoogleMaps   .

T y p e s t r a t u m a n d a g e. Basal part of Subzone IIB, Potomac Group; Early Cretaceous (early to middle Albian).

D i a g n o s i s. As for the genus.

D i m e n s i o n s. Length of flower bud (stalk excluded):

1.3 mm; diameter: 0.8 mm.

D e s c r i p t i o n a n d r e m a r k s. The flower is terminal on a long stalk that bears at least one bract that is seen as a broad scar on the pedicel ( Text-fig. 5a View Text-fig ). The flower is preserved at an early developmental stage and somewhat abraded. Tepals and stamens are not preserved, but the presence of carpels, as well as scars from tepals and stamens, show that the floral structure was multiparted and structurally bisexual. Distinct scars of two sizes indicate the presence of about 15 tepals in at least two series and 15 stamens also in at least two series ( Text-fig. 5a, b, d View Text-fig ). The arrangement of tepals and stamens is otherwise not clear. Tepals have a broad rhomboidal base and were apparently free from each other ( Text-fig. 5a, b, d View Text-fig ). Remains of stamen bases show that the stamens were free from each other and that each had a broad, flattened base ( Text-fig. 5d View Text-fig ).

The floral receptacle is conical and strongly elongated with a distinct basal collar ( Text-fig. 5a–d View Text-fig ). The gynoecium is apocarpous and consists of about 50 carpels, arranged spirally along the elongate floral receptacle. The carpels are broadly attached to the receptacle leaving a rounded scar ( Text-fig. 5a View Text-fig ). They are slightly flattened laterally with straight ventral and dorsal faces and a slightly expanded stigmatic region that is exposed towards the outer surface of the gynoecium, and sometimes appears grooved and indistinctly bifid ( Text-fig. 5d View Text-fig ). The surface of the carpel in the probable stigmatic area is irregular, perhaps due to the presence of oil cells ( Text-fig. 5c, d View Text-fig ). Carpels and ovules are not sufficiently well-preserved to show the organization clearly, but there is no distinct ventral suture visible in the SRXTM orthoslices. The carpels appear ascidiate with only one or two ovules per carpel ( Text-fig. 5c View Text-fig ).

T

Tavera, Department of Geology and Geophysics