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Paleobotany |
L. H. Bailey Hortorium, Department of Plant Biology, 228 Plant Science Building, Cornell University, Ithaca, New York 14853 USA
Received for publication November 1, 2004. Accepted for publication May 17, 2005.
ABSTRACT
A new fossil genus and species, Jerseyanthus calycanthoides, is described from the Late Cretaceous (Turonian, 
90 MYBP) Raritan Formation of New Jersey. Flowers have cupulate receptacles bearing imbricately arranged tepals that subtend a series of recurved tepals near the cup margin. Recurved tepal subtends a "stamen-staminode" pair, that includes a laminar stamen with ramified connective extensions, and an outer staminode. Outer staminodes are geniculate and incurved, and in aggregate their inner extremities define a circular area above the carpels and carpellodes. Each "stamen-staminode" pair apparently subtends (is opposite to) an inner tepal. Pollen is rounded and disulculate, with tectate columellate wall structure. Carpels are located at the center of the receptacle and have elongate styles that extend to and beyond the opening defined by the staminodal organs. Carpels are surrounded by tomentose carpellodes. Carpels include one marginally ridged seed. While these fossils do not match exactly any living species in morphology, they share numerous characters with extant members of Calycanthaceae and can be unequivocally placed within that family. Affinities of Jerseyanthus and Virginianthus were evaluated by including them in a combined analysis for the Laurales. Jerseyanthus is placed within Calycanthaceae as a sister taxon to the modern genus Calycanthus.
Key Words: angiosperms • Calycanthaceae • cladistics • Cretaceous • flowers • fossils • molecular data • morphology
Exceptionally rich deposits of angiosperm floral, fruit, and leaf remains from the Late Cretaceous of New Jersey are the subject of an ongoing study (e.g., Crepet et al., 1992
, 2004
; Herendeen et al., 1993
, 1994
; Nixon and Crepet, 1993
; Crepet and Nixon, 1994
, 1996
, 1998a
, b
; Crepet, 1996
; Weeks et al., 1996
; Gandolfo et al., 1998a
, b
, c
, 2002
, 2004
; Zhou et al., 2001
; Hermsen et al., 2003
). These deposits include exquisitely preserved fossil flowers, fruits, seeds, and wood preserved by charcoalification or less commonly by lignification. Many of the fossils retain microscopic details such as trichomes, epidermal characters, ovules/seeds within carpels, stigmatic surfaces, pollen, and in many cases complete preservation of anatomical features such as cell wall form and pitting. Thus far, these deposits have revealed the oldest flowers of hamamelidaceous affinity (Crepet et al., 1992
), oldest definitive Nymphaeales (Gandolfo et al., 2004
); flowers of the Asteridae, Ericales (sensu Chase et al., 1993
; Nixon and Crepet, 1993
; Weeks et al., 1996
), a suite of dilleniid (sensu Cronquist, 1981
) taxa including the oldest fossil flowers of capparalean affinity (Gandolfo et al., 1998a
), and those with affinities to Clusiaceae (Crepet and Nixon, 1998); a host of rosidean taxa; such as hydrangeoids (Crepet, 1996
; Crepet and Nixon, 1996
; Gandolfo et al., 1998b
), and saxifragoids (Hermsen et al., 2003
), and a variety of taxa within basal Magnoliidae (e.g., Crepet and Nixon, 1994
, 1998; Herendeen et al., 1993
, 1994
).
In this contribution, we report the presence of fossil flowers with a suite of characters found in the members of the family Calycanthaceae, particularly with the genus Calycanthus. We also evaluate the systematic position of the new fossil species and of the previously putative calycanthoid fossil flower Virginianthus using the principle of parsimony.
Modern Calycanthaceae comprises four genera of deciduous or evergreen shrubs and trees. Each genus has a very restricted distribution; Calycanthus is restricted to southwest and eastern United States, Chimonanthus to eastern Asia (Nicely, 1965
; Heywood, 1978
), Sinocalycanthus to the mountains of the Chekiang Province, eastern China (Cheng and Chang, 1963
, 1964
; Straley, 1991
) and Idiospermum (often placed in Idiospermaceae) to the rain forests of Queensland, Australia (Blake, 1972
; Heywood, 1978
). The previous oldest fossil record of the family was thought to be from the Potomac Group, Early Cretaceous of North America, based on the charcoalified fossil flower Virginianthus calycanthoides Friis, Eklund, Pedersen and Crane (Friis et al., 1994
). Other fossils recognized as belonging to Calycanthaceae include seeds from the Tertiary of Germany (Mai, 1987
), and a potential calycanthoid fossil, Araripia florifera, described as a magnoliid angiosperm from the Lower Cretaceous Crato Formation (Mohr and Eklund, 2003
).
MATERIALS AND METHODS
Fossil preparation
Fossils were isolated from silty clay collected at the Old Crossman Clay Pit in Sayreville, New Jersey. The fossil-bearing deposits are in the Raritan Formation, and on the basis of pollen analysis, are thought to represent the Amboy Fire Clay of Late Turonian Age (90 MYBP; Christopher, 1979
; Grimaldi et al., 1989
; G. J. Brenner, SUNY New Paltz). Fossils were isolated by dissolving the clay matrix in water and then carefully pouring the fossil-bearing fraction through a series of sieves. After isolation, fossils were cleaned with hydrofluoric acid, washed, and then rinsed with distilled water and allowed to air dry. Selected fossils were mounted for scanning electron microscopy (SEM), which was performed with an AMR 1000 and a Hitachi (Hitachi High Technologies American, Schaumburg, Illinois, USA) S4500 SEM.
Cladistic analysis
Fossils were added as terminals to a cladistic matrix previously published by Renner (1999
; obtained directly from the author), which included molecular and morphological data for a selection of taxa commonly included in the Laurales. Renner (1999)
based the morphological matrix on another previously published matrix (Renner et al., 1997
), which can be consulted for discussion of character states and data sources. Renner's combined matrix includes 28 taxa (25 core lauralean taxa, plus three outgroups), 15 morphological characters, and 4402 molecular characters (rbcL, rpl16, trnT-trnL, trnL-trnF, atpB-rbcL, and psbA-trnH) of which 898 were informative. Two different analyses were performed in our study; one where Jerseyanthus was included within the combined morphological/molecular matrix and a second one including two fossil taxa, Jerseyanthus and the previously published Virginianthus calycanthoides from the Potomac Group (Friis et al., 1994
). For both fossil taxa, characters 2 through 9 of Renner's matrix were coded. For Jerseyanthus characters 11 and 13 were coded as well. Characters were coded for Jerseyanthus as character 2, floral cup present (1); character 3, innermost tepals free (0); character 4, fixed stamen number present (1); character 5, basal filament glands absent (0); character 6, anther dehiscence longicidal (0); character 7, pollen apertures disulculate (2); character 8, carpels several free (0); character 9, epigyny absent (0); character 11, ovules polymorphic (0, 1, 2, 3); and character 13, fruit type achene (1). For Virginianthus, the characters were coded as character 2, floral cup present (1); character 3, innermost tepals free (0); character 4, fixed stamen number present (1); character 5, basal filament glands absent (0); character 6, anther dehiscence longicidal (0); character 7, apertures monosulcate (0); character 8, carpels several free (0); character 9, epigyny absent (0). In addition, we added a new character, "food bodies," that was coded for all the taxa, both extant and fossil. For the extant taxa (except for Calycanthus) and Virginianthus, the character food bodies was scored as absent (0), while for Calycanthus and Jerseyanthus it was scored as present (1). All molecular characters and the remaining morphological characters were coded as missing for both fossils. Parsimony analyses were performed using NONA (Goloboff, 1998
) and the parsimony ratchet (Nixon, 1999
) implemented through Winclada (Nixon, 2002
). Ten sets of 200 iterations using a 10% perturbation of characters were used for the ratchet analyses.
RESULTS
Systematics
Order
Laurales Lindley 1833.
Family
Calycanthaceae Lindley 1819 nom. conserv.
Genus
Jerseyanthus Crepet, Nixon, et Gandolfo gen. nov.
Type species
Jerseyanthus calycanthoides Crepet, Nixon et Gandolfo sp. nov.
Generic diagnosis
Flowers bisexual, actinomorphic/pleiomorphic, and pedicellate; receptacle cupulate, somewhat campanulate, bearing 40–50 imbricate tepals externally; distal rank (at rim of cupule) of tepals ovate and slightly recurved; androecium in one cycle, consisting of 12 "stamen-staminode" pairs near the rim of the cupule, staminodes and stamens in two series; each "stamen-staminode" pair complex subtended by a single tepal; "stamen-staminodes" pair composed of single flattened, stalked, incurved staminode subtending and opposite (to the outside of) a single apparently fertile dithecal stamen; fertile stamens fleshy, without noticeable filament, the two separate thecae not embedded, attached marginally/abaxially, staminal dehiscence "valvate" (dehiscence slit I-shaped, with a complete longitudinal dehiscence and short lateral dehiscence lines at the base and apex of the anther), latrorse to extrorse; endothecium one-layered with U-type thickenings; connective extended into a biparted ramified "antler" or "candelabrum" with 6–8 branches terminating in spheres ("food bodies") with ornamented surfaces; pollen grains rounded, disulculate; cupulate receptacle clothed inside with densely packed long simple trichomes extending to the mouth; gynoecium basal within the cupulate receptacle; carpels free, ca. 24, conduplicate, laterally compressed, style solitary, narrow, geniculate at the base, typically extending to mouth of receptacular cupule; carpellodes present, ca. 24, exterior to the fertile carpels; ovule number unknown; seed one per carpel, marginally attached.
Specific diagnosis
As for the genus.
Holotype
CUPC 1483.
Paratypes
CUPC 1484–1502.
Etymology
The generic name Jerseyanthus reflects the location of the fossil bearing strata and the species name calycanthoides refers to the family Calycanthaceae.
Type locality
Old Crossman Clay Pit, Sayreville, New Jersey, USA.
Stratigraphic position
South Amboy Fire Clay, Raritan Formation.
Age
Turonian, Late Cretaceous.
Detailed description
Flowers hermaphroditic, actinomorphic, 1.3–2.8 mm in height and 1.5–3 mm in diameter (Figs. 1–7). Pedicels (broken) 0.5–0.9 mm in diameter and at least 0.6 mm in length, bearing a dense indumentum of elongate simple hairs; stele of pedicel with at least a ring of vascular bundles, and additional vascular bundles; vessels and scalariform perforation plates are present (Figs. 7–9). Receptacles cup-shaped or slightly campanulate, with seven to eight ranks of external, imbricate tepals; 30–50 tepals ovate and/or triangular, entire or irregularly lobed, 0.7 mm–1.9 mm in length; tepal surfaces (adaxial and abaxial) clothed with a dense indumentum composed of apparently simple hairs (Figs. 1, 2, 4, 5); they sometimes have an elongate central lobe (Fig. 6). Near the distal portion of the receptacle, the tepals are thinner, ovate, expanded, sparsely tomentose at the base and glabrous at the apex, recurved at a 75° to 90° angle from the axis. In the uppermost series, at the rim of the receptacle, each tepal is outside of and aligned with a "stamen-staminode" pair (Figs. 2, 3). Androecium composed of an apparent two series of organs, an outer series of staminodes and an inner of stamens attached to the rim of the receptacle, forming ca. 12 "stamen-staminode" pairs; each "stamen-staminode" pair comprises one staminode opposite and to the outside of (developmentally subtending) one stamen (Figs. 10–13). Staminodes 0.9–1.4 mm in length, inflexed, overarching and extending almost to the center of the flower (Figs. 12–14), with well-defined stalks, geniculate, with an enlarged, laminar distal portion above the geniculus (Figs. 12, 13). Staminode stalks vascularized (Fig. 15); distal portion of each staminode lancelolate, with elongate marginal/adaxial (but due to inflection, these are on the "lower" surface) lacunae that apparently opened linearly and are similar to pollen sacs, but lack pollen in known specimens (Figs. 12, 14). Stamens with thickened connective, without appreciable filament, dithecal (tetrasporangiate?) with separated marginal/abaxial thecae; anther dehiscence extrorse/latrorse, valvate (slit I-shaped, longitudinally dehiscent with short lateral dehiscence at base and apex); endothecium single-layered with U-type thickenings (Figs. 16–19). Stamen connective extended beyond the apex of the anthers, the extension prominent, bilateral and branched, candelabrum or antler-like, with six to eight diminishing branches, each branch terminating in a small globose structure with a textured surface (229– 567 µm in width; Figs. 12, 16, 19, 20), that are interpreted as "food bodies." Pollen grains usually solitary (found in situ in the pollen sacs), varying considerably in size (17–38 µm by 16–32 µm), disulculate (Figs. 21–22), and sporadically preserved in apparent tetrahedral tetrads (Fig. 23). Exine psilate-perforate, probably columellate with a thick foot-layer (Figs. 23, 24). Gynoecium apocarpus; carpels ca. 24, 425–720 µm long excluding the style, glabrous, arranged in base of receptacle cup, intergrading to the exterior with sterile carpels (carpellodes) (Figs. 25–29). Carpels have a single adaxial suture line (Fig. 27). Styles solitary, geniculate (the knee inflexed) at the base, unbranched, at least some (and probably typically) extending through the narrow mouth of the receptacle (Figs. 26, 28), stigma unknown. Carpellodes tomentose (Figs. 26, 31). Seed solitary, slightly elongate, with a peripheral ridge (Figs. 29, 30). Receptacle with elongate simple hairs that are borne in tufts among the carpels and carpellodes and extend at least to the opening of the receptacle (Fig. 26–28).
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Comparative morphology
Jerseyanthus is remarkably similar in overall morphology, form, and arrangement of floral organs to flowers in the modern family Calycanthaceae (Figs. 32–37; 39–41). Our phylogenetic analyses confirm this relationship, placing the fossils within the "crown group" of modern Calycanthaceae (Fig. 38). Although Jerseyanthus flowers are similar to those of modern Calycanthaceae, there are some interesting and distinctive differences between these fossil flowers and those of the modern genera. Overall, Jerseyanthus is clearly more similar to the modern genera, Calycanthus and Chimonanthus than to Sinocalycanthus and Idiospermum.
For example, Jerseyanthus and Idiospermum differ in several characters. Idiospermum is characterized by its sessile flowers, its gynoecium (which consists of one, rarely two to five carpels, Worboys, 2003
), its fleshy sessile stigma, petal-like stamens and monosulcate pollen grains (Blake, 1972
; Wilson, 1976
). Jerseyanthus does not share any of these features, which are typically used to separate Idiospermum from other Calycanthaceae (or place it in its own family, Idiospermaceae; Blake, 1972
; Sterner and Young, 1980
; Cronquist, 1981
). Significant morphological differences are also noticeable when comparing Jerseyanthus and Sinocalycanthus. The receptacle of Sinocalycanthus is flattened or bowl shaped, it has a "reduced" perianth composed of only five bracteous tepals, 9– 11 petaloid tepals and the same number of connivent tepals. Its androecium is composed of 18–19 laminar stamens, ca. 7– 9 staminodes, 11–12 carpels (Cheng and Chang, 1963
, 1964
; Straley, 1991
), and lacks food bodies (Vogel, 1998
). In contrast, Jerseyanthus has a cup-shaped receptacle, a perianth composed of more numerous and less petaloid tepals, an androecium with no more than 12 stamens and very elaborate connective extensions (that include "food bodies"), 12 different and distinctive outer staminodes, and a gynoecium composed of ca. 24 carpels.
As mentioned previously, Jerseyanthus is most similar to the modern genera Calycanthus and Chimonanthus and, based on the phylogenetic analysis, is most closely related to Calycanthus. The perianths of Calycanthus, Chimonanthus (Nicely, 1965
), and the fossil taxon are each composed of imbricate tepals with trichomes covering both surfaces. One notable difference is in the number of tepals, which varies from 30 to 50 in the fossil and from 15 to 30 in both modern genera. The tepals of the fossil flowers are irregularly lobed, and the innermost/uppermost ones are proportionally smaller relative to receptacle size than those in these modern genera (which presumably therefore have more "showy" flowers). The tepals of both the extant genera (Nicely, 1965
) and Jerseyanthus are similarly covered by a dense indumentum.
The most interesting features of the fossils, that distinguish them from modern taxa, are the consistent presence of large inflexed staminodes that overarch the stamens, and the branched, candelabra-like connectives with multiple food bodies. Although similar staminodes can be sporadically found in some flowers of modern Calycanthus, they are never consistently present nor regular in number as in the fossil. The elaborate candelabrum-like connective extensions of the fossil have never been reported in modern taxa, and in Calycanthus, connective extensions are unbranched with a single terminal food body. We interpret the spheres on the connective of the fossil flowers as "food bodies" due to positional homology with the single food body found in modern Calycanthus (Fig. 20, Grant, 1950
; Rickson, 1979
). In Calycanthus, food bodies regularly occur on the stamen connectives, and in contrast to the fossils, occasionally are found on the tips of staminodes and inner tepals. The modern food bodies are not reported to be textured like those of the fossil genus, but we are uncertain if this texture is real or preservational. Chimonanthus lacks food bodies entirely (Nicely, 1965
). Jerseyanthus, Calycanthus, and Chimonanthus have approximately the same number of stamens. The fossil specimens consistently have exactly 12 fertile stamens, while Calycanthus usually has 10–18 stamens (12–14 is most common). Chimonanthus has between five and 10 stamens (Nicely, 1965
). Pollen grains of Calycanthus, Chimonanthus and the fossil are globose (collapsed in our specimens) and disulculate (Walker, 1974
, 1976
). Nevertheless, only Calycanthus and Jerseyanthus have a more or less psilate exine with tectal perforations, while pollen of Chimonanthus has typical fossulate-rugulate exine without tectal perforations (Walker, 1976
). The pollen grains of Jerseyanthus are smaller (17–38 µm) than those of the extant species (45–60 µm; Erdtman, 1986
).
Staminodia are present between the gynoecium and stamens in all the modern genera of Calycanthaceae (e.g., Fig. 37); and these may be homologous with what seem to be carpellodes in Jerseyanthus. Note that despite the fact that Jerseyanthus carpellodes lack food bodies and appear to be modified carpels based on common morphological characteristics, they share common position, indumentum, and occasional carpel-like morphology (e.g., Fig. 2b in Grant, 1950
), with "staminodes" of extant Calycanthus. However, and of considerable interest, is the additional, uncommon and heretofore unreported form of staminode that is sometimes found in modern Calycanthus (Figs. 35, 36). This newly discovered type of staminode is both large relative to the functional stamens and exterior to them (Figs. 35, 36). While these "external" staminodes occur only sporadically in modern Calycanthus and then are not regularly associated with each fertile stamen—we have observed specimens with only 3–4 such staminodes— they consistently subtend each stamen in Jerseyanthus. External staminodes of Calycanthus and Jerseyanthus are alike in several aspects including relative size, incurved disposition, the short pedicel or filament, and the distal expansion with lateral/adaxial pollen saclike lacunae (Figs. 12–14, 35, 36).
Finally, in Jerseyanthus, the "stamen-staminode" pairs are delimited from inner organs by abaxially folded inner staminodes. These structures have an acute tip, and they are clothed with hairs (Figs. 4, 11, 16). Organs interior to these tepals are either carpel-like without indication of seeds (the "carpellodes" discussed above) or carpels with seeds (Figs. 6, 25, 26). To our knowledge, modern Calycanthaceae do not have such tepals interior to the androecium. The gynoecia of the fossil species and all modern Calycanthaceae are apocarpous, at the base of the receptacle. Extant calycanths lack carpellodes in contrast to the obvious carpellodes of Jerseyanthus, but Jerseyanthus carpellodes occur outside of the carpels in the same relative position as the staminodes in modern Calycanthus (Figs. 25, 26), and they intergrade with these in morphology as noted. While the relatively greater similarity of these organs to carpels in Jerseyanthus could be explained by their being unpollinated and aborted, the apparently number (ca. 24) of fertile carpels and consistent differences in indumentum between the carpels and carpellodes argues against such an interpretation. Carpels of both Jerseyanthus and Chimonanthus are glabrous, while Calycanthus carpels are pubescent (Endress and Igersheim, 1997
). The carpels and carpellodes of Jerseyanthus are similar in shape, but the carpellodes are tomentose with long simple hairs (Figs. 26, 31). The style of both extant and fossil species are free, geniculate at the base, filiform, and are extended through the mouth of the receptacle (Nicely, 1965
; Endress and Igersheim, 1997
). Although the exact number of ovules for the fossil is unknown, one marginal ovule developed into a single seed in each carpel in our specimens (Figs. 29, 30). Modern Calycanthaceae carpels bear two ovules, and one aborts while the other one develops into a seed (Endress and Igersheim, 1997
).
Taxonomic placement
The decision to recognize Jerseyanthus as a genus distinct from Calycanthus was based on several criteria. As with almost all fossils, no matter how well preserved and how many features are available, incomplete information always increases the ambiguity of placement. With Jerseyanthus, we have no information on vegetative features. It certainly is possible, though unlikely, that with additional data the phylogenetic placement of Jerseyanthus could shift. More importantly, among the known features of Jerseyanthus are those not found in extant species of Calycanthus (the number and consistency of androecial parts, the consistent and regular outer whorl of staminodes, and the branched stamen connectives). Based on parsimony analyses, these distinctive features place Jerseyanthus outside of the "crown group" of Calycanthus. Inclusion of Jerseyanthus within the genus Calycanthus would then require an expansion of the concept of Calycanthus, including a revised delimitation and morphological description of the genus. Given these caveats regarding fossils and their placement, we believe the most conservative approach is to place the fossil in a distinct genus characterized by the unique features of branched stamen connectives. In this way, it is not necessary to amend the description of Calycanthus, and if future data suggest a different placement of Jerseyanthus, there will not be a need for nomenclatural changes nor additional amendment to the description of Calycanthus.
Comparison with the fossil Virginianthus calycanthoides
Friis et al. (1994)
described a Calycanthus-like flower, Virginianthus calycanthoides, from the Early-Middle Albian Puddledock locality of the Patapsco Formation, Potomac Group, exposed in Virginia, USA. This bisexual (hermaphroditic) flower consists of a cup-shaped, urceolate hypanthium (receptacular cupule) that contains free carpels in the base of the receptacle chamber. Its receptacle is characterized by 6–8 broad ribs, elongate simple hairs, and a series of protuberances that are interpreted as an indication of the presence of oil glands. In addition, the hypanthium has a perianth, consisting of at least 12 tepals arranged in two cycles, situated externally and close to its rim. The androecium of Virginianthus is composed of 30–40 laminar stamens arranged around the rim of the receptacle in a very tight spiral. Between the stamens and the carpels are additional structures that can be interpreted as staminodes or carpellodes. The stamens are tetrasporangiate and open by valvate dehiscence, and although the two pairs of sporangia are separated by a narrow connective, they have a well-developed ventral and apically expanded connective extension. Pollen grains found in situ are monosulcate (monocolpate), reticulate, and more or less circular in equatorial view, and ca. 15 µm. The gynoecium has ca. 18–26 naked carpels placed centrally on the receptacle in 3–4 series; each carpel is laterally flattened and bears at least two lateral seeds. Friis et al. (1994)
pointed out that Virginianthus shares characters of the four modern genera (Idiospermum included) of the Calycanthaceae, but did not undertake a formal cladistic analysis of the taxa. The position of Virginianthus in Calycanthaceae has been previously questioned because Virginianthus has a "higher number of stamens, and further differs in having embedded pollen sacs with valvate dehiscence and monocolpate reticulate pollen grains" (Eklund, 1999
, p. 30). Our analyses indicate that Virginianthus is a more plesiomorphic/generalized member of Laurales or possibly does not belong in Laurales at all. Such a placement is consistent with its relative age (it is older). Placement within the modern calycanth clade is not warranted for Virginianthus, and it cannot be nested within the modern crown group.
Although Jerseyanthus and Virginianthus share some general features (presence of "hypanthium," arrangement of androecium and the free carpels), these are also shared with modern Calycanthaceae as well as other Laurales and some other magnoliid groups, and there are no particular features to suggest a close relationship for these two fossils, as supported by our cladistic analysis. Jerseyanthus is thus the oldest verified member of the calycanth clade, and Virginianthus may or may not represent the oldest known floral remains of the broader Laurales.
Flower or pseudanthium?
The organization, position, and nature of the structures in the fossil flower open the possibility that it is a pseudanthial structure composed of multiple flower homologues. Each "stamen-staminode" pair in the fossil is delimited by a tepal to the outside and a large staminode that has what appears to be sterile, adaxial pollen sacs (facing inward in the flower). Directly opposite and to the inside of this inward-facing staminode is a fertile stamen with abaxial anther sacs (outward facing) and inward from this is an outward-facing "tepal." Thus, each "stamen-staminode" pair is organized as two opposed tepals that enclose a fertile stamen and a staminode, which face each other. If this complex is interpreted as a single floral unit, the stamen and staminode would both be interpreted as having adaxial anther sac positions, instead of one adaxial and the other abaxial, in a unisexual (staminate) flower. The presence of tepals to the inside of the androecium may also be suggestive a pseudanthial origin for the fossil flower. However, there seems to be no way to test such an hypothesis without additional fossil material that shows a transition between an inflorescence (perhaps something like a chloranthaceous, monoecious inflorescence) and a cupulate, condensed inflorescence with a more obvious retention of individual floral units. Thus, for the time being, we interpret Jerseyanthus and by implication all Calycanthaceae as having large, complex, but simple flowers, not pseudanthia.
Pollination syndrome
Kubitzki (1993)
considered all extant Calycanthaceae to be cantharophilous. Nevertheless, Vogel (1998)
observed that Chimonanthus flowers are clearly melittophilous. Chimonanthus flowers, as mentioned, lack food bodies and produce nectar in the peristomatic nectarioles of the petals (Vogel, 1998
), that attract honeybees. Calycanthus flowers are protogynous. They lack nectaries but they produce food bodies at the tips of the innermost tepals, stamens, and staminodia; these food bodies are considered to have a nutritive function (Calycanthus "food" is rich in protein; Rickson, 1979
) and therefore attract beetles within the receptacle. In conjunction with the food bodies, the hairs on the surfaces of the tepals and the staminodes are part of the pollination mechanism (Grant, 1950
). In C. occidentalis the process is described as follows: the beetles enter the flower toward the center of the receptacle where they are trapped for 1 to 2 days. Once inside, the beetles eat the food bodies and as the anthers dehisce the body of the beetles are covered with pollen grains, after which the flowers open and the beetles leave them carrying the pollen. Although we cannot prove that this was the mechanism that occurred in Jerseyanthus, the scenario is reasonable based on the morphology (the elaborate food bodies on the candelabrum-like connective extension, the position of the staminodes, and the presence of hairs on the tepals, on the "stamen-staminode" pair tepals and on the carpellodes). Fossil beetle parts (including Curculionidae; Crepet and Nixon, 1998b
; W. Crepet, unpublished data) are present in the same sediments but have not been found immediately associated with fossil flowers of any kind.
Conclusions
In this study, the presence of a new fossil taxon, Jerseyanthus calycanthoides is established for the Turonian flora of New Jersey. The fossils show a mosaic of characters found in modern Calycanthaceae and share more characters with Calycanthus than with other extant members if the family.
When Jerseyanthus was included in a phylogenetic analysis, it was unequivocally placed within modern Calycanthaceae as a sister taxon of Calycanthus. When the other putative Cretaceous fossil representative of Calycanthaceae, Virginianthus, was also included in the analysis Jerseyanthus remained as sister taxon to Calycanthus within Calycanthaceae, while Virginianthus came out in an unresolved position basal within, or outside of, the remaining families of the Laurales. This exercise illustrates the importance of cladistic methodology in evaluating the affinities of fossils, which often have a mosaic of plesiomorphic and derived features.
FOOTNOTES
1 The authors thank Jennifer Svitko for SEM and laboratory preparations, Professor Susanne Renner, Systematic Botany, Ludwig-Maximilians University, Munich, for providing lauralean data matrices necessary to evaluate the phylogenetic position of the fossil taxon Jerseyanthus, and Michael Rothman for his reconstructions of Jerseyanthus. This research was supported by National Science Foundation Grant DEB 0108369 to W.L.C. and K.C.N. 
2 Author for correspondence (e-mail: WLC1{at}cornell.edu
)
LITERATURE CITED
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