Ptelea” eocenica Berry, 1930

Na, Yuling, Blanchard, Jane & Wang, Hongshan, 2019, Fruits, seeds and flowers from the Puryear clay pit (middle Eocene Cockfield Formation), western Tennessee, USA, Palaeontologia Electronica (a 49) 23 (3), pp. 1-57 : 44-50

“ Ptelea” eocenica Berry, 1930

Figure 60

1930 Ptelea eocenica Berry , p. 92, pl. 41, fig. 4.

Description. Fruit a samara, consisting of one or two fusiform endocarps and a wing. The endocarp ca. 3 mm long and 2 mm wide. Fruit wing 7 mm long and 9 mm wide, with finely reticulate venation; apex rounded. Pedicel slender, ca. 8 mm long and 0.5–1 mm wide.

Number of specimens examined. 3. UF15820- 059403, CONN-Q2-03, CONN-Q3-07.

Remarks. Berry (1930) described a specimen from the Grand Junction locality in Hardeman County, Tennessee and assigned it to Ptelea eocenica . Manchester and O’Leary (2010, pp. 73–75, figure 24a) reexamined Berry’s specimen and suggested that the thickness of the pedicel (too thick to be that of Ptelea ), perianth scar, fusiform locular area (endocarp), and organization of venation are similar to those of extant fruits of Craigia and Maxwellia and tentatively placed this specimen under fossil Malvaceae . Call and Dilcher (1995) suggested that the affinities of this fruit are best considered unresolved, which we agree with. The fossil resembles fruits of Ptelea in size and shape. However, other features, including the persistent remains of a floral disc at the base of the wing, trinervate venation of the wing, and ellipsoidal endocarp shape, which would confirm its identity as Ptelea , are not evident. The perianth scars of these Puryear specimens, including one specimen described by Berry (1930), are not as obvious as suggested by Manchester and O’Leary (2010). In this report, we follow Call and Dilcher (1995) and treat the affinities of these Puryear fruits as unresolved.

Claiborne Fruit/Seed Type 2

Figure 61

Description. Fruit/fruiting heads laterally compressed, spatulate?, 1.2–1.5 cm long and 2.0– 2.2 cm wide, bearing 6–7 apically split appendages 6– 11 mm long and 2–4 mm wide. A disc-like receptacle present, 20 mm. Peduncle/pedicel stout, 7 mm long and 4 mm wide.

Number of specimens examined. 5. UF15820- 002240, 059485, UF15815-008198, 053095.

Remarks. Wang et al. (2013, pp. 57–58, figure 51) described two specimens from the Warman clay pit, Tennessee. After comparison with specimens with similar morphology from the Miocene flora of the Meuro and Rauno sequences in the Lusatica region (Saxony and Brandenburg, Germany) (Mai 2001, pl. 8, figures 16–24), Wang et al. (2013) suggested that these specimens possibly represent a member of Fagaceae with acorns already dispersed and the appendages probably represent elongate cupular scales. All attached scales seem to be oriented in one direction.

Another possibility is that these specimens, including those from the Warman locality (Wang et al., 2013, pp. 57–58, figure 51), are compressions/ impressions of Cornerocarpon copiosum Grote (Wang et al., 2013, p. 30, figures 22, 23; Figure 61.3 , 4 ), because of the spatulate fruit/fruiting head with apically split appendages attached on one side of the disc-like receptacle. A major difference is that the appendages of this fruit/seed type (6–11 mm long and 2–4 mm wide) are longer than the “tepals” of Cornerocarpon copiosum (ca 6 mm long and 2.2–5.0 mm wide)

Claiborne Fruit/Seed Type 6

Figure 62

Description. Compressed fruit/seed ca. 1.4 cm in diameter with a reticulate surface pattern. Exterior margin smooth.

Number of specimens examined. 1. UF15820- 043597.

Remarks. This specimen belongs to the same fruit/seed type from the Bovay locality, Mississippi (Blanchard et al., 2016, figure 50.3), but lacks fibers.

Claiborne Fruit/Seed Type 11

Figure 63

Description. Disseminule narrowly elliptic, 5 mm long and 2.5 mm wide; an apical extension ca. 3 mm long and 0.2 mm wide, decurrent along one side and extending to the base of the disseminule; two lateral attachments present on the same side of the disseminule.

Number of specimens examined. 2. UF15820- 061123.

Remarks. This disseminule probably represents a monocot (grass) fruit. It differs from Carpolithus boldensis from the Bolden locality, Mississippi (Blanchard et al., 2016, p. 42, figure 47) in that C. boldensis has a thin awn, a lemma and a seed body.

Claiborne Fruit/Seed Type 12

Figure 64

Description. Spherical fruit ca. 3.5 mm in diameter, with an apical projection ca. 0.5 mm long. Pedicel stout, ca. 2 mm long and 0.3 mm wide.

Number of specimens examined. 1. UF15820- 061144.

Remarks. Compared with “ Copaifera ” yeguana Berry (Wang et al., 2013, p. 53, figure 46), the Puryear fruit is smaller in size, and its mesocarp is probably very thin. As in “ Copaifera ” yeguana Berry, this fruit probably had a stony seed, indicated by the depression of the center of the compressed specimen. The apical projection probably represents a persistent style.

Claiborne Fruit/Seed Type 13

Figure 65

Description. Capsular fruit, loculicidally dehiscent, with at least three curved valves; valve ca. 2.3 cm long and 1.1 cm wide, notched at the apex; one elliptic seed impression, ca. 1.8 cm long and 1 cm wide present at the center of each valve; a marginal zone ca. 2–3 mm wide present on both sides of each valve, except at the notched apex.

Number of specimens examined. 1. UF15820- 059205.

Remarks. This specimen probably represents a capsule that is dehiscent and releases seeds when the fruit is mature. The number of valves and locules and the number of seeds are unknown. The elliptic impression on each valve probably represents the shape of the seed.

The valves of this fruit differ from those of Andrewsiocarpon puryearensis ( Figure 30 , this paper), a loculicidally dehiscent capsule with five valves and winged seeds, in that they lack a medial ridge and an apical beak, and that they are shorter and wider (2.3 cm long and 1.1 cm wide vs 2.5–3 cm long and 9 mm wide).

Claiborne Fruit/Seed Type 14

Figure 66

Description. Obovate fruit ca. 2.5 cm long and 1.7 cm at the widest point. Fruit wall ca. 2 mm thick enclosing ca. seven–eight seeds each ca. 5–7 mm in diameter. Pedicel ca. 10 mm long and 2 mm wide.

Number of specimens examined. 1. UF15820- 059406.

Remarks. This fruit is similar to Claiborne Infructescence Type 1 (Wang et al., 2013, p. 41, figure 31; Figure 48 ). However, this specimen represents a fruit, rather than an infructescence, because the seeds are enclosed within a fruit wall (probably exocarp and mesocarp) that is about 2 mm thick. The individual seeds of this fruit are larger than the individual fruits of Claiborne Infructescence Type 1.

Claiborne Fruit/Seed Type 15

Figure 67

Description. A partially opened fruiting structure showing two overlapping bracts enclosing another structure with a prominent middle ridge/groove. The bracts separate, ca. 7 mm long and ca. 2 mm wide tapering to an acute apex, fine striations present.

Number of specimens examined. 1. UF15820- 059466, 059466’.

Remarks. The bract of this structure is similar in size and shape to one of the dispersed (or detached) bracts reported from the Puryear locality by Berry (1930, p. 143, pl. 48, figure 24). However, the striations are not as pronounced.

This specimen possibly represents a grass spikelet. It differs from the monocot disseminule, Carpolithus boldensis , from the Bolden locality, Mississippi (Blanchard et al., 2016, p. 42, figure 37) in the absence of an awn at the distal end of the bracts.

Claiborne Fruit/Seed Type 16

Figure 68

Description. Laterally compressed ovoid fruiting structure ca. 2 cm long and ca. 1.5 cm at the widest point. Pedicel ca. 1 cm long and 0.3 cm wide. Mesocarp ca 1.5–2 mm thick. No seeds distinguishable.

Number of specimens examined. 1. UF15820- 059479.

Remarks. In gross morphology, this specimen is similar to Bignonicapsula formosa Berry (Berry, 1930, p. 132, pl. 43, figure 3). However, this fruit/

seed type from Puryear does not have flat, winged seeds inside the capsule. It is possible that this specimen represents a single-seeded legume pod such as Copaifera .

Claiborne Fruit/Seed Type 17

Figure 69

Description. Laterally compressed obovate fruit/ seed ca. 2 cm long (excluding pedicel) and 1.5 cm wide at the middle. Margin entire. Pedicel ca. 3.8 mm long and 1 mm wide.

Number of specimens examined. 2. UF15820- 059455, 059486.

Remarks. One specimen only shows the attachment scar at the base. A smaller specimen (UF15820-059486) is similar in shape with pedicel attached. The rough surface is possibly due to a difference in preservation.

Claiborne Fruit/Seed Type 18

Figure 70

Description. Laterally compressed ovate fruit/ seed 6 mm long and 3 mm wide. Pedicel incomplete, ca. 3.5 mm long and 1.5 mm wide. Apical spine 2 mm long.

Number of specimens examined. 1. CONN-Q09- 02.

Remarks. This fruit/seed type has a relative strong pedicel and an apical spine.

Claiborne Fruit/Seed Type 19

Figure 71

Description. An incomplete winged fruit including a circular fruit body (ca. 6 mm in diameter) covered with spines (ca. 3 mm long and 0.1–0.3 mm wide) and a wing (at least 12 mm wide) with radiating veins.

Number of specimens examined. 1. CONN-Q1- P19.

Remarks. The combination of a circular fruit body covered with spines and a wing with radiating veins can be used to distinguish this fruit type from Paleooreomunnea stoneana Dilcher, Potter and Crepet (Berry 1930, p. 60, pl. 46, figures 11, 12; Dilcher et al., 1976, p. 539, figures 26–32; Manchester, 1987, p. 59, figure 28E–L; Wang et al., 2013, p. 23–24, figure 19) and Claiborne Fabaceae Fruit Type 1. Because only one incomplete specimen is examined, we tentatively assign this specimen within Angiosperm Incertae Sedis.

Plant Insertae Sedis - Undetermined

Claiborne Bract Type 1

Figure 72

Description. Bract orbicular to lanceolate in outline, varying from 20 mm long and 14 mm wide to 10 mm long and 3 mm wide; margin entire; base concave, clasping, overall shape slightly cordate to auricular; apex tapering abruptly or gradually to an acute apex; venation parallel and extending directly to the apex in the middle portion of the lamina; lateral veins branching or parallel in the basal portion and convergent when close to the margin; lamina heavily pubescent, covered with trichomes about 0.2–0.3 mm long.

Number of specimens examined. 14. UF15820- 059462, 059452, 059454, 059456.

Remarks. The two specimens described by (Berry, 1930) pl. 48, figs 24, 25) are also from the Puryear locality and they probably belong to the same type. As Berry suggested, these specimens probably represent bracts or bud scales of plants with unknown affinities.

Figures

FIGURE 4. Claiborne Arecaceae Fruit Type 1: UF15820-059477, laterally compressed fruit with fibers. Note that curved fibers (indicated by arrows) extend from the base to beyond the apex of the fruit. Scale bar equals 2 mm.

FIGURE 30. Andrewsiocarpon puryearensis sp. nov. 1) UF15820-61133, specimen showing five seeds (s) and four valves (v). Note the central columella is inferred by the circular depression (indicated by the white arrow) and the fifth valve is inferred by the depression at the bottom of the capsule (indicated by the black arrow). Scale bar equals 5 mm; 2) UF15820-059410, showing two laterally compressed valves, pedicel (p), and a central columella (c). Scale bar equals 5 mm.

FIGURE 48. Claiborne Infructescence Type 1: UF15820-059475, infructescence with helically arranged fruits. Scale bar equals 2 mm.

FIGURE 60. “Ptelea” eocenica Berry, 1930: 1) CONN-Q2-03, specimen showing a fruit with two fusiform seeds; 2) CONN-Q3-07, specimen showing reticulate venation of fruit wing; 3) UF15820-059403, specimen showing pedicel, fruit wing, and a fusiform seed. All scale bars equal 2 mm.

FIGURE 61. Claiborne Fruit/Seed Type 2: 1) UF15820- 002240, laterally compressed fruit/fruiting head with apically split appendages (indicated by arrow); 2) UF15820-059485, laterally compressed spatulate fruit/ fruiting head with a stout peduncle/pedicel (indicated by arrow). Cornerocarpon copiosum Grote (compressed, charcoalized fossil specimens for comparison): 3) UF15815-008198, laterally compressed fruit showing a peduncle (indicated by arrow); 4) 15815-53095, laterally compressed fruit showing broken bracts (indicated by arrows). All scale bars equal 3 mm.

FIGURE 62. Claiborne Fruit/Seed Type 6: UF15820- 043597, compressed fruit/seed with a reticulate surface pattern. Scale bar equals 2 mm.

FIGURE 63. Claiborne Fruit/Seed Type 11: UF15820- 061123, specimen showing an elliptic disseminule with an apical extension that is decurrent on one side and extends to the base (indicated by four white arrows). Note two overlapping lateral attachments (indicated by black arrows). Scale bar equals 1 mm.

FIGURE 64. Claiborne Fruit/Seed Type 12: UF15820- 061144, showing an orbicular fruit with an apical projection at the distal end (indicated by arrow) and a stout pedicel at the base (indicated by arrow). Scale bar equals 1 mm.

FIGURE 65. Claiborne Fruit/Seed Type 13: UF15820- 059205, showing incomplete, dehiscent capsule with three valves observed. Note seed impression (s), two marginal zones on each valve (indicated by white arrows), and the notched valve apices. Scale bar equals 5 mm.

FIGURE 66. Claiborne Fruit/Seed Type 14: UF15820- 059406, fruit with seven seeds enclosed in fruit wall (indicated by arrows). Scale bar equals 3 mm.

FIGURE 67. Claiborne Fruit/Seed Type 15: 1, 2) UF15820-059466, 059466', part and counterpart of a specimen show two overlapping bracts enclosing another structure with a prominent middle ridge/grove (indicated by arrows). All scale bars equal 1 mm.

FIGURE 68. Claiborne Fruit/Seed Type 16: UF15820- 059479, laterally compressed ovoid fruiting structure. Scale bar equals 3 mm.

FIGURE 69. Claiborne Fruit/Seed Type 17: 1) UF15820-059455, laterally compressed obovate reproductive structure; 2) UF15820-059486, a smaller fruit/seed with an attached pedicel. All scale bars equal 2 mm.

FIGURE 70. Claiborne Fruit/Seed Type 18: CONN-Q09- 02, laterally compressed fruit/seed with attached pedicel and apical spine. Scale bar equals 2 mm.

FIGURE 71. Claiborne Fruit/Seed Type 19: 1) CONN- Q1-P19, specimen showing circular fruit body with spines and an incomplete wing. Scale bar equals 4 mm; 2) Enlargement of the lower left of Figure 71.1 to show spines. Scale bar equals 1 mm; 3) Enlargement of Figure 71.1 to show veins (indicated by arrows) Scale bar equals 1 mm.

FIGURE 72. Claiborne Bract Type 1: 1) UF15820-059452, an orbicular bract with auricular base on one side and slightly cordate base on the other side. Note parallel veins in the middle and convergent veins on two lateral sides of the bracts; 2) Enlargement of Figure 72.1 to show trichomes; 3) UF15820-059456, bract with a cordate base; 4) UF15820-059454, an ovate bract. Note parallel veins in the middle and convergent veins on lateral sides of the bract; 4) UF15820-059462, a lanceolate bract. All scale bars equal 3 mm, except in Figure 72.2, which equals 1 mm.