Corresponding author: Denis Michez (
Academic editor: Jes Rust
Although bees are one of the major lineages of pollinators and are today quite diverse, few well-preserved fossils are available from which to establish the tempo of their diversification/extinction since the Early Cretaceous. Here we present a reassessment of the taxonomic affinities of
Dewulf A, De Meulemeester T, Dehon M, Engel MS, Michez D (2014) A new interpretation of the bee fossil
Bees (
The highly fossiliferous shales of Florissant, Colorado have revealed 34 species and 19 genera belonging to several extant bee families:
Photograph of holotype female of
Given that
Dataset for the geometric morphometric analysis including 360 specimens from 109 species and 15 subfamilies. N = number of specimens.
FAMILY | SUB-FAMILY | SPECIES | N |
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5 | |
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5 | |
5 | |||
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1 | |||
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1 | |||
1 | |||
1 | |||
1 | |||
1 | |||
1 | |||
1 | |||
1 | |||
1 | |||
1 | |||
2 | |||
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5 | ||
5 | |||
5 | |||
5 | |||
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5 | ||
5 | |||
5 | |||
5 | |||
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5 | |
5 | |||
5 | |||
5 | |||
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1 | ||
5 | |||
3 | |||
2 | |||
3 | |||
1 | |||
1 | |||
4 | |||
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5 | |
5 | |||
5 | |||
5 | |||
1 | |||
1 | |||
1 | |||
1 | |||
1 | |||
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1 | ||
2 | |||
1 | |||
5 | |||
1 | |||
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5 | |||
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5 | ||
5 | |||
1 | |||
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2 | ||
3 | |||
2 | |||
5 | |||
5 | |||
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5 | |
5 | |||
1 | |||
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2 | |
5 | |||
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5 | ||
3 | |||
3 | |||
5 | |||
5 | |||
1 | |||
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3 | |||
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5 | |||
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2 | |||
5 | |||
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1 | |||
1 | |||
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1 | |||
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Taxonomic affinities of the fossil were evaluated based on wing shape. Wing venation is used widely in insect taxonomy and can provide many informative features for phylogenetic analyses and for many Late Paleozoic taxa is sometimes the only form of available data (e.g.
The right forewings of 360 female specimens were initially photographed using an Olympus SZ010 binocular coupled with a Nikon D70 camera. Photographs were gathered in one TPS file using tps-UTIL 1.56 (
Right forewing of a female of
Prior to the assignment of the fossil, shape variation within the reference dataset and discrimination of the different taxa was assessed by Linear Discriminant Analyses (LDA) of the projected aligned configurations of landmarks, with subfamily levels as
Taxonomic affinities of the fossil were assessed based on their score in the predictive discriminant space of shapes. After superimposition of the 368 landmark configurations (i.e. corresponding to the reference dataset and the fossil), aligned coordinates of the 360 specimens from the reference dataset were used to calculate the LDA. We included
In order to assess the taxonomic affinities of
The regression coefficient between the Procrustes distances and the Euclidean distances is close to 1 (0.9999). This means that the linear tangent space closely approximates the shape space, thereby permitting us to be confident in the variation amplitude of our dataset.
In LDA space with subfamily
Cross-validation assignment in LDA space with subfamily
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HR (%) | |
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20 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 100 |
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- | 33 | - | 1 | - | - | - | - | - | - | - | - | - | - | - | 97 |
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- | - | 20 | - | - | - | - | - | - | - | - | - | - | - | - | 100 |
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- | 1 | - | 19 | - | - | - | - | - | - | - | - | - | - | - | 95 |
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- | - | - | - | 13 | - | - | - | - | - | - | - | - | - | - | 100 |
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- | 1 | - | - | - | 24 | - | - | - | - | - | - | - | - | - | 96 |
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- | - | - | - | - | - | 7 | - | - | - | - | - | - | - | - | 100 |
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- | - | - | - | - | - | - | 117 | - | - | - | - | - | - | - | 100 |
|
- | - | - | - | - | - | - | - | 20 | - | - | - | - | - | - | 100 |
|
- | - | - | - | - | - | - | - | - | 20 | - | - | - | - | - | 100 |
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- | - | - | - | - | - | - | - | - | - | 11 | - | - | - | - | 100 |
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- | - | - | - | - | - | - | - | - | - | - | 5 | - | - | - | 100 |
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1 | - | - | - | - | - | - | - | - | - | - | - | 10 | - | - | 91 |
|
- | - | - | - | - | 1 | - | - | - | - | - | - | - | 16 | - | 94 |
|
- | - | - | - | - | - | - | - | - | - | - | - | - | - | 20 | 100 |
All of the 109 specimens of
Distribution of extant examined andrenid (36 specimens) and the eight landmark configurations of
The genus presently includes only the type species,
♀: Forewing with three submarginal cells, first submarginal cell largest, second smallest; r-rs long, about as long as anterior border of second submarginal cell; anterior border of second submarginal cell not dramatically shorter than that of third submarginal cell; 1rs-m relatively straight; 2rs-m greatly arched apical in posterior half; 1m-cu entering second submarginal cell near midpoint; 2m-cu entering third marginal cell at apical third of cell length, 2m-cu relatively straight; pterostigma linear, much longer than wide, border inside marginal cell relatively straight; marginal cell with acutely rounded apex, not truncate or appendiculate, apex on costal margin, apical most abscissa Rs relatively straight such that marginal cell apex tapers gradually in width from 2rs-m to apex. Pilosity well developed; flocculus absent; scopa present on metafemur and metabasitarsus; metabasitarsus more than half as long as metatibia; pretarsal claws with minute inner tooth. ♂: Unknown.
The new genus-group name is a combination of
The wings of
Assuming that its clustering among
Wing shape analyses were successfully employed in previous studies to discriminate extant bee taxa at various classificatory levels, from subspecies to tribes (e.g.,
Based on the discovery that Cockerell’s fossil
The bees of the Florissant shale have been ignored for a long time (
We sincerely thank the University of Colorado Museum of Natural History (Boulder, USA) and Dena Smith and Talia Karim for making it possible to study Cockerell’s holotype of