Corresponding author: Peter Wilf (
Academic editor: Sandy Knapp
Leaves are the most abundant and visible plant organ, both in the modern world and the fossil record. Identifying foliage to the correct plant family based on leaf architecture is a fundamental botanical skill that is also critical for isolated fossil leaves, which often, especially in the Cenozoic, represent extinct genera and species from extant families. Resources focused on leaf identification are remarkably scarce; however, the situation has improved due to the recent proliferation of digitized herbarium material, live-plant identification applications, and online collections of cleared and fossil leaf images. Nevertheless, the need remains for a specialized image dataset for comparative leaf architecture. We address this gap by assembling an open-access database of 30,252 images of vouchered leaf specimens vetted to family level, primarily of angiosperms, including 26,176 images of cleared and x-rayed leaves representing 354 families and 4,076 of fossil leaves from 48 families. The images maintain original resolution, have user-friendly filenames, and are vetted using
Wilf P, Wing SL, Meyer HW, Rose JA, Saha R, Serre T, Cúneo NR, Donovan MP, Erwin DM, Gandolfo MA, González-Akre E, Herrera F, Hu S, Iglesias A, Johnson KR, Karim TS, Zou X (2021) An image dataset of cleared, x-rayed, and fossil leaves vetted to plant family for human and machine learning. PhytoKeys 187: 93–128.
General patterns of angiosperm leaf architecture, the shape and venation characters of leaves, are well known for very few of the more than 400 angiosperm families. The development of a standard descriptive terminology (
To build their knowledge of leaf architecture, researchers still rely primarily on “oral tradition” from a dwindling number of knowledgeable colleagues and a handful of survey papers and field guides that emphasize purportedly diagnostic leaf features (
Machine-vision algorithms, as seen in popular applications such as LeafSnap (
Increasing general knowledge of leaf architecture for both human and machine learners depends on the development of customized, accessible, vetted visual libraries that allow rapid morphological comparisons of a high phylogenetic diversity of extant and fossil leaves. The recent proliferation of digitized plant-image resources comprises an invaluable reference for plant morphology, already including tens of millions of digitized herbarium sheets on portals and aggregator sites such as JStor Global Plants (
Cleared or x-rayed leaves from phylogenetically diverse taxa, selectively sampled from vouchered herbarium sheets, remain the most valuable visual reference for comparative study of leaf architecture because they have a similar visual presentation, with high capture of venation detail and comparatively few distractors. Existing collections of this type are fragile, mostly made decades ago as references for fossil leaf identification by selecting leaves from herbarium sheets, then either chemically clearing the specimens of most tissues other than veins and mounting them on glass slides or x-ray imaging them, in either case with extreme care and effort. Most cleared-leaf collections suffer from deterioration of the mounting media, which obscures large areas of the leaves; thus, photographic archiving offers a form of visual preservation before further degradation occurs. The largest and best-known cleared-leaf collections are those of the late Drs. Jack A. Wolfe and Leo J. Hickey, together now forming the National Cleared Leaf Collection (
For the many users who may find it challenging to visit these collections in person for suitable lengths of time, many cleared and x-rayed leaf collections are already accessible from various websites or in print. These valuable resources include the
Isolated fossil leaves present an additional set of challenging problems (e.g.,
Here, we meet the community need for a specialized dataset of leaf images by consolidating a set of original-resolution photographs of vouchered extant and fossil specimens (Fig.
Selected image pairs of confamilial extant and fossil (see Appendix
Summary of component datasets.
Collection | Collection type | #Images | #Families | #Genera, approx. | #Species, approx. | Repository | Collection numbers† | Other data and images‡ |
---|---|---|---|---|---|---|---|---|
cleared leaves | 16,249 | 267 | 3,893 | 12,439 | USNM | secondary |
|
|
cleared leaves | 6,861 | 313 | 1,678 | 5,723 | USNM | secondary |
|
|
Axelrod Cleared Leaves | cleared leaves | 832 | 89 | 270 | 641 |
|
primary |
|
Wing X-Rays | x-ray negatives | 2,234 | 26 | 416 | 890 | USNM | secondary | n/a |
|
26,176 | 354 | 4,573 | 17,385 | ||||
Florissant, |
fossil leaves | 666 | 23 | 47 | 73 | several | secondary |
|
Florissant, |
fossil leaves | 2,654 | 21 | 40 | 70 |
|
primary |
|
General fossil collection | fossil leaves | 756 | 39 | 93 | 135 | several | primary | n/a |
|
4,076 | 48 | 129 | 222 |
Abbreviations:
The full image dataset and supporting data files are available open-access for download in a single Figshare Plus data collection at
The cleared and x-rayed leaf-image collections included here were chosen for availability of a large number of botanically diverse, high-quality images, accessible voucher data, and open-access re-use permissions. The collections primarily represent non-monocot (“dicot”) angiosperm leaves, with minor representation of monocots, other vascular plant groups, and non-foliar plant organs. Several other large cleared and x-rayed leaf collections exist (see Introduction) but were not used in the dataset presented here for various reasons. For example, the significant cleared-leaf atlas series by
A master inventory of the 26,176 images of cleared and x-rayed specimens from >4,500 genera and >17,300 extant species in 354 plant families (Table
Catalog numbers of cleared or x-rayed leaves in the master inventory (available in the accompanying Figshare archive) refer to a unique glass slide (for the cleared leaves) or a film-negative number (for the x-rays) used to organize the respective collection, as designated by the creator of the collection. The catalog numbers of the cleared and x-rayed leaf collections are usually secondary, i.e., specific to the collection but linked in museum records (as legacy data and thus without hyperlinks) to a primary source voucher at a herbarium (Table
Family and order updates were done iteratively by first doing automatic lookups to family of the catalog genera and species, using the tables provided in The Plant List (
For reference, we note other online resources for batch-vetting plant names that we did not use, including Taxonomic Names Resolution Service (
Due to the intensive labor that would be required to update the large number of names below family level, even with the aid of batch services, and the emphasis here on family-level vetting, generic and species names were for the most part not updated except to correct misspellings that would hinder future lookups. A full vetting below family level would also require manually consulting and hyperlinking all the primary herbarium records to check for new determinations, a process of several years. However, any user can easily find taxa of interest using the specimen list provided (accompanying Figshare archive) and access updated nomenclature and voucher data using the resources listed.
The resulting master inventory of cleared and x-rayed leaves was manually inspected repeatedly to eliminate variant spellings and other inconsistencies, until no more were found. Even after this stage, many issues remained from duplicate and corrupt files, invalid paths, labeling errors, ghost folders of problem images, and other common legacy database errors. Automated and reproducible data analysis and cleaning was done (by J. Rose and R. Saha) largely in Jupyter Notebooks and scripted in Python. In an iterative process, we used the Pandas library to load, sort, and filter the dataset in the form of a table, mapping metadata values in each column to unique specimens in each row. From there, we verified each file path’s full compliance with a pair of requirements, namely that it be both (a) a unique absolute path, and (b) a valid path specifying an existing, uncorrupted image file that can be successfully opened and closed. Rows that failed this test were flagged and taken out for manual review.
Further file path cleaning included the use of a fuzzy matching algorithm, through which all possible matches between a flagged query file path
Once all taxonomic and archival fields were validated, we assigned each sample a new filename that accomplishes both (a) directly encoding multiple levels of metadata into human-readable format within the filename, and (b) allowing easy sorting and searching of files on disk, without any additional alterations or struggling with a full relational database. The new filename format is constructed in the form: “Family_Genus_species_Collection_Catalog number”. This user-friendly format facilitates, for the first time, rapid alphabetic sorting, visual inspection, and searching of all the merged images from multiple sources in standard personal-computer windows and visual browsers. In the filenames, as just described, the family is updated to
The National Cleared Leaf Collection is derived from parallel, broadly collaborative efforts supervised by the late Drs. Jack A. Wolfe (
The Wolfe contribution (
Following Dr. Wolfe’s retirement in 1992, S. Wing supervised the moving and curation of the cleared-leaf collection from Denver to
The
Professor Leo J. Hickey supervised the assembly of a parallel cleared-leaf collection to Wolfe’s during his time as curator of paleobotany at
The Daniel I. Axelrod Cleared Leaf Collection at
In the early 1990s, S. Wing developed an x-ray scanning technique (
We provide 4,076 vouchered leaf-fossil images of specimens that are assigned to family level, in total covering 44 angiosperm and four non-angiosperm families from a variety of sites in the AmeriCAS that are well known to the authors (Table
Unlike the images from the cleared and x-rayed collections, which were not adjusted except for cropping of the x-rays, the fossil-leaf images were all manually and reversibly rotated, close-cropped, and contrast- and temperature-adjusted (all whole-image adjustments, other than cropping) in Adobe Camera Raw so that they are approximately similar in relative frame alignment and overall contrast, with emphasis on making vein features visible (for some photographs taken on early-model digital cameras with barrel distortion in macro mode, the lens distortion was corrected manually using Adobe Camera Raw). This procedure minimizes strong distractors such as rock matrix for machine learning of fossil leaves, an interest of several of the authors (
The fossil set of 4,076 images is comprised of two parts (Table
The late Eocene Florissant Fossil Beds Lagerstätte of Colorado is known worldwide for its long history of collection and investigation, its outstanding diversity of plant and animal fossils, and its seminal role in the conservation movement (
Among its many distinctions, the Florissant biota was one of the first large fossil assemblages of any kind to be photographed, cataloged comprehensively, and made openly available in an internet database (
The first of two components of the Florissant image set (Table
The second component of the Florissant image collection provided here (Table
The general collection of 756 fossil leaf images provided here (Appendix
Major contributions to the general collection are briefly listed here for paleobotanists, with additional taxonomic and occurrence references listed in Appendix
The dataset presented here consolidates thousands of hours of labor by many people (see Acknowledgments) into a single accessible platform. Due to the extraordinary effort involved, it is unlikely that many new, large-scale cleared and x-rayed leaf collections will ever be assembled and digitally processed. Thus, the future prospects for significantly increasing the overall sample size and improving the coverage of taxonomy and geography in digital leaf-reference collections most likely lie elsewhere. The greatest potential appears to come from the advancing techniques for segmenting and enhancing leaf images from the enormous, widely available resource of digitized herbarium sheets (
We look forward to seeing the assembled image dataset catalyze advances in research, education, and outreach. The images and supporting data are available open-access on Figshare Plus at
Funding for this work came from NSF grants EAR-1925755, EAR-1925481, and EAR-1925552 (PW, TS, MAG, and others); DEB-1556666 and DEB-1556136 (PW, MAG, and others); and the National Park Service (HWM).
Many researchers, staff, students, and volunteers contributed to the development of the collections aggregated here over many years. These include the investigators named in the manuscript, the collectors and field crews who made the primary collections around the world, and the collections staff, technicians, and volunteers at the numerous involved herbaria and fossil repositories. We further acknowledge the following, with apologies for any missing names. Assistance in the original assembly of the
Species list for fossil-leaf images.
Species | #Images | Source, age, region† | References |
---|---|---|---|
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64 | Florissant, late Eocene, Colorado, USA |
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|
|
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100 | Florissant, late Eocene, Colorado, USA | ||
153 | Florissant, late Eocene, Colorado, USA | ||
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9 | Florissant, late Eocene, Colorado, USA | ||
1 | Florissant, late Eocene, Colorado, USA | ||
55 | Florissant, late Eocene, Colorado, USA | ||
|
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9 | Florissant, late Eocene, Colorado, USA | ||
|
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2 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
2 | Florissant, late Eocene, Colorado, USA | see |
|
4 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
1 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
1 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
|
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4 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia | ||
|
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2 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
|
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3 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
|
|||
33 | Florissant, late Eocene, Colorado, USA | ||
|
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9 | Laguna del Hunco, early Eocene, Chubut, Argentina | ||
|
|||
“ |
2 | Little Mountain & Bonanza, early (LM) and middle (B) Eocene, Wyoming (LM) & Utah (B), USA | |
|
|||
4 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
1 | Laguna del Hunco, early Eocene, Chubut, Argentina | P. Wilf, unpubl. obs. | |
21 | Florissant, late Eocene, Colorado, USA | ||
5 | Republic, early Eocene, Washington, USA | ||
27 | Little Mountain & Bonanza, early and middle Eocene, Wyoming & Utah, USA | ||
22 | Florissant, late Eocene, Colorado, USA | ||
175 | Florissant, late Eocene, Colorado, USA | ||
5 | Florissant, late Eocene, Colorado, USA |
|
|
|
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1 | Wasatch Fm., early Eocene, Wyoming, USA | ||
|
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16 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
|
|||
15 | Florissant, late Eocene, Colorado, USA | ||
11 | Florissant, late Eocene, Colorado, USA | ||
|
|||
33 | Republic, early Eocene, Washington, USA | ||
1 | Wasatch Fm., early Eocene, Wyoming, USA |
|
|
4 | Republic, early Eocene, Washington, USA | ||
1 | Republic, early Eocene, Washington, USA |
|
|
3 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
58 | Florissant, late Eocene, Colorado, USA | ||
|
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3 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
|
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2 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
12 | Republic, early Eocene, Washington, USA | ||
13 | Fort Union Fm., several sites, early & late Paleocene, Montana, North Dakota, & Wyoming, USA | ||
|
|||
3 | SW Wyoming, several sites, late Paleocene, Wyoming, USA | ||
6 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
3 | Republic, early Eocene, Washington, USA | ||
2 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
4 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
|
|||
13 | Salamanca Fm., early Paleocene, Chubut, Argentina | ||
9 | Laguna del Hunco, early Eocene, Chubut, Argentina | ||
|
|||
1 | Republic, early Eocene, Washington, USA | ||
Rhododendron sp. RP53 | 1 | Republic, early Eocene, Washington, USA | |
|
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4 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
1 | Wasatch Fm., early Eocene, Wyoming, USA | ||
|
|||
9 | Little Mountain & Bonanza, early and middle Eocene, Wyoming & Utah, USA | ||
13 | Florissant, late Eocene, Colorado, USA | ||
21 | Florissant, late Eocene, Colorado, USA | ||
23 | Florissant, late Eocene, Colorado, USA | ||
21 | Florissant, late Eocene, Colorado, USA |
|
|
1 | Salamanca Fm., early Paleocene, Chubut, Argentina | ||
14 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
15 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia | ||
3 | Little Mountain, early Eocene, Wyoming, USA |
|
|
3 | Cogua & Nemocón mines, late Paleocene, Cogua, Cundinamarca, Colombia |
|
|
1 | Little Mountain, early Eocene, Wyoming, USA | ||
1 | Florissant, late Eocene, Colorado, USA | ||
6 | Bonanza, middle Eocene, Utah, USA | ||
30 | Little Mountain & Bonanza, early and middle Eocene, Wyoming & Utah, USA | ||
“ |
23 | Florissant, late Eocene, Colorado, USA | |
39 | Florissant, late Eocene, Colorado, USA | ||
|
|||
15 | Florissant, late Eocene, Colorado, USA | ||
17 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
cf. |
2 | Little Mountain, early Eocene, Wyoming, USA |
|
2 | Republic, early Eocene, Washington, USA | ||
521 | Florissant, late Eocene, Colorado, USA | ||
9 | Florissant, late Eocene, Colorado, USA | ||
1 | Florissant, late Eocene, Colorado, USA | ||
9 | Florissant, late Eocene, Colorado, USA | ||
11 | Florissant, late Eocene, Colorado, USA | ||
12 | Florissant, late Eocene, Colorado, USA | ||
8 | Florissant, late Eocene, Colorado, USA | ||
37 | Florissant, late Eocene, Colorado, USA | ||
46 | Florissant, late Eocene, Colorado, USA | ||
|
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3 | Florissant, late Eocene, Colorado, USA | ||
|
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2 | Republic, early Eocene, Washington, USA | ||
|
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1 | Florissant, late Eocene, Colorado, USA | ||
|
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3 | Republic, early Eocene, Washington, USA | ||
|
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53 | Florissant, late Eocene, Colorado, USA | ||
1 | Bison Basin, late Paleocene, Wyoming, USA | ||
1 | Little Mountain, early Eocene, Wyoming, USA |
|
|
7 | Fort Union Fm., several sites, early & late Paleocene, Montana & Wyoming, USA | ||
1 | Wasatch Fm., early Eocene, Wyoming, USA | ||
1 | Wasatch Fm., early Eocene, Wyoming, USA | ||
|
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“ |
1 | Battleship, Maastrichtian, North Dakota, USA | |
1 | Wasatch Fm. several sites, early Eocene, Wyoming, USA |
|
|
17 | Salamanca Fm., early Paleocene, Chubut, Argentina | ||
21 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
8 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
6 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA |
|
|
12 | Salamanca & Peñas Coloradas fms., early Paleocene, Chubut, Argentina | ||
4 | Florissant, late Eocene, Colorado, USA | ||
18 | Little Mountain, early Eocene, Wyoming, USA | ||
5 | Hell Creek Fm., several sites, Maastrichtian, North Dakota, USA | ||
2 | Madeline’s Bank, Hell Creek Fm., Maastrichtian, North Dakota, USA | ||
11 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
“ |
2 | Florissant, late Eocene, Colorado, USA | |
“ |
6 | Republic, early Eocene, Washington, USA | |
|
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1 | Madeline’s Bank, Hell Creek Fm., Maastrichtian, North Dakota, USA | ||
|
|||
“ |
1 | Wasatch Fm., several sites, early Eocene, Wyoming, USA | |
16 | Laguna del Hunco, early Eocene, Chubut, Argentina | ||
3 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia | ||
6 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia | ||
1 | Republic, early Eocene, Washington, USA | ||
4 | Little Mountain, early Eocene, Wyoming, USA | ||
|
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35 | Florissant, late Eocene, Colorado, USA | ||
3 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
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1 | Little Mountain, early Eocene, Wyoming, USA |
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6 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
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1 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
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1 | Cerrejón mine, middle-late Paleocene, Guajira Peninsula, Colombia |
|
|
1 | Salamanca Fm., early Paleocene, Chubut, Argentina | ||
|
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1 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
|
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1 | Republic, early Eocene, Washington, USA | ||
|
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13 | Laguna del Hunco, early Eocene, Chubut, Argentina | ||
16 | Florissant, late Eocene, Colorado, USA | ||
1 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
5 | Little Mountain, Bonanza, & Wasatch Fm., early and middle Eocene, Wyoming & Utah, USA | ||
|
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15 | Hell Creek Fm., several sites, Maastrichtian, North Dakota, USA | ||
8 | Hell Creek Fm., several sites, Maastrichtian, North Dakota, USA | ||
5 | Hell Creek Fm., several sites, Maastrichtian, North Dakota, USA | ||
4 | Fort Union Fm., several sites & Republic, late Paleocene, early Eocene, Washington & Wyoming, USA | ||
9 | Little Mountain & Bonanza, early and middle Eocene, Wyoming & Utah, USA | ||
7 | Hell Creek Fm., several sites, Maastrichtian, North Dakota, USA | ||
21 | Fort Union Fm., several sites, early & late Paleocene, Montana, North Dakota, & Wyoming, USA | ||
1 | Little Mountain, early Eocene, Wyoming, USA |
|
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|
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32 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
9 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
1 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
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|
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1 | Wasatch Fm., several sites, early Eocene, Wyoming, USA | ||
15 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
|
1 | Battleship, Maastrichtian, North Dakota, USA | ||
4 | Rancho Grande, early Paleocene, Chubut, Argentina | ||
11 | Florissant, late Eocene, Colorado, USA | ||
|
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10 | Florissant, late Eocene, Colorado, USA | ||
146 | Florissant, late Eocene, Colorado, USA | ||
33 | Florissant, late Eocene, Colorado, USA | ||
4 | Florissant, late Eocene, Colorado, USA | ||
10 | Florissant, late Eocene, Colorado, USA | ||
6 | Republic, early Eocene, Washington, USA | ||
2 | Florissant, late Eocene, Colorado, USA | ||
2 | Florissant, late Eocene, Colorado, USA | ||
1 | Florissant, late Eocene, Colorado, USA | ||
3 | Republic, early Eocene, Washington, USA | ||
4 | Florissant, late Eocene, Colorado, USA | ||
2 | Republic, early Eocene, Washington, USA | ||
23 | Florissant, late Eocene, Colorado, USA | ||
2 | Republic, early Eocene, Washington, USA |
|
|
2 | Florissant, late Eocene, Colorado, USA |
|
|
8 | Republic, early Eocene, Washington, USA | ||
52 | Florissant, late Eocene, Colorado, USA | ||
7 | Florissant, late Eocene, Colorado, USA | ||
|
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2 | Little Mountain, early Eocene, Wyoming, USA | ||
93 | Florissant, late Eocene, Colorado, USA | ||
3 | Bonanza, middle Eocene, Utah, USA | ||
4 | Bonanza, middle Eocene, Utah, USA | ||
1 | Wasatch Fm., several sites, early Eocene, Wyoming, USA | ||
8 | Bonanza, middle Eocene, Utah, USA | ||
15 | Florissant, late Eocene, Colorado, USA | ||
2 | Florissant, late Eocene, Colorado, USA |
|
|
|
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36 | Florissant, late Eocene, Colorado, USA | ||
3 | Fort Union Fm., several sites, late Paleocene, Wyoming, USA | ||
10 | Little Mountain & Bonanza, early and middle Eocene, Wyoming & Utah, USA | ||
106 | Florissant, late Eocene, Colorado, USA |
|
|
16 | Florissant, late Eocene, Colorado, USA | ||
“ |
5 | Little Mountain & Bonanza, early and middle Eocene, Wyoming & Utah, USA | |
“ |
41 | Florissant, late Eocene, Colorado, USA | |
28 | Florissant, late Eocene, Colorado, USA | ||
18 | Laguna del Hunco, early Eocene, Chubut, Argentina |
|
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|
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2 | Republic, Wasatch Fm., early Eocene, Washington & Wyoming, USA | ||
|
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2 | Republic, early Eocene, Washington, USA | ||
|
|||
1 | Republic, early Eocene, Washington, USA | ||
9 | Fort Union Fm., several sites, early Paleocene, Montana, North Dakota, & Wyoming, USA | ||
1 | Republic, early Eocene, Washington, USA | ||
|
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978 | Florissant, late Eocene, Colorado, USA | ||
30 | Little Mountain & Bonanza, early and middle Eocene, Wyoming & Utah, USA | ||
1 | Wasatch Fm. several sites, early Eocene, Wyoming, USA | ||
8 | Republic, early Eocene, Washington, USA | ||
30 | Florissant, late Eocene, Colorado, USA | ||
|
|||
“ |
11 | Florissant, late Eocene, Colorado, USA |
† Fossil sites listed are only those that sourced the fossils in this dataset and may not include type localities and other occurrences of the species. ‡ Occurrence reference for the dataset in this paper, when different from the taxonomic reference. §