Trigonobalanoidea americana Crepet and Nixon, 1989
|
publication ID |
https://doi.org/ 10.26879/1042 |
|
persistent identifier |
https://treatment.plazi.org/id/03F087C8-FFDF-FFBC-FCDD-C80FFEE3FE4C |
|
treatment provided by |
Felipe |
|
scientific name |
Trigonobalanoidea americana Crepet and Nixon, 1989 |
| status |
|
cf. Trigonobalanoidea americana Crepet and Nixon, 1989
Figure 21 View FIGURE 21
Description. Incomplete laterally preserved unbranched axis with seven fruits attached; fruits orbicular, ca. 3.8 mm in diameter with three to four apical projections ca. 0.5 mm long, each with a longitudinal groove; axis ca. 2.8 cm long and 0.8 mm wide; pedicels ca. 1.5 mm long and 0.5 mm wide; persistent perianth parts present. No cupules or cupule scales are observed.
Number of specimens examined. 1. UF15820- 061130.
Remarks. This specimen probably represents a mature infructescence of Trigonobalanoidea americana (Crepet and Nixon, 1989) . A major difference between the specimens from the Puryear and Bovay localities (Blanchard et al., 2016, p. 15, figure 14) and those from the type locality (Buchanan, Tennessee; Crepet and Nixon, 1989) is that the Puryear and Bovay specimens lack the fruit wings described by Crepet and Nixon (1989). Our Puryear specimen shows fruits with pedicels but lacking cupules and cupule scales.
Claiborne Fagaceae Fruit Type 2
Figure 22 View FIGURE 22
Description. Cupulate fruits 3.5–5 cm long and 2.2–5 cm wide; cupule spiny; spines simple, apically curved, ca. 0.7–1.5 cm long, covered with simple trichomes; spines concentrically arranged on the cupule, area of cupule enclosing nut/nutlets 2.5–3.0 cm long and 2.0– 2.5 cm wide. Attachment scar of the cupule 3 mm in diameter.
Number of specimens examined. 9. UF15820- 004016, 004016', 004020, 032202, 061121.
Remarks. Wang et al. (2013, p. 23, figure 16. 3) reported one specimen assignable to this morphotype from the Warman clay pit, Tennessee. The specimens from the Puryear locality provide more characters than the Warman specimen and warrant a separate fruit type for these large cupulate fruits with simple spines.
It seems that cupules of this fruit type entirely enclose the fruits. The number of nuts that each cupule encloses is unknown. Vertically compressed cupules ( Figure 22.3 View FIGURE 22 ) show the width of the pedicels, but their length and how they are attached to the axis are unknown.
Based on the presence of unbranched, stout spines on the cupule that do not obscure its surface (see Figure 22.1 View FIGURE 22 ; Nixon, 1997), this fruit type is probably closely related to the genus Fagus .
Table 3 lists the major characters of Claiborne Fagaceae Fruit Types 1 to 6 and Catahoulea grahamii , a fagaceous fruit from the Oligocene Catahoula Formation Huntsville, Texas, with similar morphology.
Claiborne Fagaceae Fruit Type 5
Figure 23 View FIGURE 23
Description. Cupule 2–2.5 cm long and 1.8–2 cm wide (including spines); cupule valves at least two, spiny; basal portions of the spines intertwined, forming a web-like pattern with laminal tissues within the network. Distal portions of the spines simple or branched. Simple trichomes present on the spines and lamina tissue. Peduncle not observed. Nuts/Nutlets not observed.
Number of specimens examined. 3. UF15820- 004015, 004025, 032853.
Remarks. Wang et al. (2013, p. 26, figure 17.1–3) described one specimen from the Warman clay pit, Tennessee and included it in Claiborne Fagaceae Fruit Type 3. Blanchard et al. (2016, pp. 18–20, figure 15.5) assigned it to a new type, Claiborne Fagaceae Fruit Type 5, because of its large fruit size and its stout, relatively long peduncle ( Table 3). One specimen ( Figure 23.2 View FIGURE 23 ) shows that the cupule has at least two valves, indicating that it probably has multiple nutlets.
The absence of the distal portions of the spines probably indicates that the Puryear specimens were transported some distance before being deposited and preserved.
Claiborne Fagaceae Fruit Type 6
Figure 24 View FIGURE 24
Description. Cupulate fruits 19–23 mm long and 17–20 mm wide; nutlet spiny, 11–15 mm long and 4–15 mm wide (excluding spines); spines simple, straight or curved, ca. 3–4 mm long and 0.2–0.3 mm wide.
Number of specimens examined. 3. UF15820- 004019, 059411.
Remarks. This type differs from other Claiborne fagaceous fruits in having a relatively small number of short, straight to slightly curved spines and a smaller fruit size ( Table 3). Figure 24.1 View FIGURE 24 seems to show that at least three cupules are clustered and attached to an axis.
Mindell et al. (2007) established a fossil taxon, Cascadiacarpa spinosa Mindell, Stockey and Beard , based on 80 anatomically preserved specimens of spiny, cupulate fruits from the Eocene Appian Way locality of Vancouver Island, British Columbia, Canada. The Puryear specimens and C. spinosa are similar in their small number of short, straight spines. They differ in that the spines of C. spinosa are branched and are often borne in clusters, and its spiny cupule encloses a single nut entirely with the exception of the apical stylar protrusion of the pistil.
Mindell et al. (2014) described another species, Cascadiacarpa exilis , from the Eocene Appian Way locality of Vancouver Island, British Columbia. These permineralized, fagaceous cupulate nuts are borne on a spiny stalk and are broadly ovate in longitudinal and transverse section. The cupules are valvate and have both branching and simple spines. The cupule of C. exilis enclosed a single, ovoid, sclerotic nut entirely, except at the apex, where a stylar protrusion is free from any surrounding tissues. The two different modes of preservation (permineralized vs. compressed) make it difficult to compare these fossils, even though their sizes are similar and they both have simple spines.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.