Fig 1.
Morphology and terminology of Edestus whorl and tooth.
(A) Traditional linear measures and geometric landmarks (LM) for individual teeth. (B) Multiple teeth comprise a whorl and are ejected from the anterior end as illustrated. W = crown width; H = crown height; uh = upper height; uw = upper width; lh = lower height; D = distance from crown point to point.
Table 1.
Type specimens and figure references for previously defined Edestus species considered in this study.
Fig 2.
(A) E. heinrichi crown, AMNH 466G. (B) X-ray of two small whorls of E. heinrichi, FMNH HQ 492 B-2. (C) E. minor crown, GSM 49368. (D) E. triserratus tooth, FMNH UC 2092. (E) E. triserratus tooth, GSM 31410. Scale bar same for A-E. (F) E. minor associated upper and lower whorls, USNM 7255; (G) X-ray of subadult E. triserratus associate upper and lower whorls with anterior jaws, FMNH PF 8047. Note two crowns lacking bases forming at posterior of upper whorl (arrow). (H) Adult E. triserratus upper whorl, CAS specimen, oriented with (I) similarly-sized lower whorl of E. triserratus, AMNH 485. (J) E. heinrichi whorl, AMNH 488 cast, plastotype. (K) E. heinrichi whorl, USNM V 182450. (L) E. heinrichi whorl, AMNH 6049. (M) X-ray of E. heinrichi whorl, FMNH HQ 26. (N) E. heinrichi tooth, FMNH HQ 1374 A3. (O) E. vorax, AMNH 225, note that all crown apices have been repaired. Scale bar same for G-O. Images C, E courtesy of British Geological Survey.
Fig 3.
Upper and lower Edestus whorls.
Renders from 3D laser scanned specimens. (A) E. vorax lower whorl, ANSP 9989, holotype. (B) E. minor, lower whorl, cast of FMNH PF 2317. (C) E. heinrichi upper whorl, ANSP 22391. (D) E. heinrichi upper whorl, ANSP 22392. (E) E. heinrichi upper whorl, ANSP 22396. (F) E. heinrichi lower whorl, ANSP 22373. (G) E. heinrichi lower whorl, ANSP 22393. Scale bar same for all.
Fig 4.
Occlusal curvature of Edestus tooth whorls.
(A) Symmetric-crowned whorls. (B) Asymmetric-crowned whorls. Upper whorls have solid lines, lower whorls are dashed.
Fig 5.
Crown dimensions for all studied Edestus specimens.
Symbology corresponds to revised species designations. Holotype specimens of originally defined Edestus species have colored symbols; see Table 1 for specimen identification. Holotype abbreviations: c = E. crenulatus; g = E. giganteus; h = E. heinrichi; k = E. karpinskyi; min = E. minor; mir = E. mirus; pri = E. pringlei; s = E. serratus; t = E. triserratus; pro = E. protopirata; v = E. vorax.
Table 2.
Tooth metrics for Edestus specimens.
Table 3.
Tooth metrics for asymmetric-crowned Edestus specimens.
Fig 6.
Geometric morphometrics of all Edestus specimens.
Type specimens are outlined with black circles. Holotype E. mirus crowns from upper and lower whorls shown in red and blue circles, respectively.
Fig 7.
Geometric morphometrics of Edestus with symmetric-crowned teeth.
(A) PCA of all crowns color-coded by crown width size to show ontogenetic variation. Holotypes have outlined circle symbol. (B) Five whorls from ANSP provide PC1 shape of consecutive crowns plotted by crown width. Holotypes have outlined circles filled white. Note significant outlier E. giganteus holotype above the y-axis excursion.
Fig 8.
Geometric morphometrics of Edestus with asymmetric-crowned teeth.
(A) PCA of all crowns color-coded by crown width size to show ontogenetic variation. Multiple crowns from holotype E. mirus from both upper and lower whorls outlined. All holotypes have black outlined circle symbol. Diamond symbol denotes specimens plotted in the upper grouping of B. (B) PC2 plotted by crown width. Light and dark grey convex hulls demark morphospace of two groups of crowns. (C) PC2 of all asymmetric crowns correlates strongly with the upper ratio metric. (D) Ratio of linear measures distinguishing two asymmetric crown types for Edestus, based on geometric ordination and groupings in B. (E) Discriminant analysis of asymmetric crown using linear measurements classified by groupings shown in B and D. Holotype specimens of E. triserratus, E. minusculus, and E. kolomnensis form the upper group (pink); Holotypes of E. mirus (multiple crowns), E. pringlei, and E. minor form lower group (blue). Loadings for linear measurements (see Fig 1) on the discriminant axis.
Table 4.
Nonparametric tests for new groupings of Edestus specimens from principle components analysis.
Results of PERMANOVA (F = 174.9, p = 0.0001) and ANOSIM (R = 0.93, p = 0.0001).
Table 5.
Crown height to width ratio for new Edestus groupings.
Results of ordinary least squares regression of log-transformed values.
Fig 9.
Illustration of revised Edestus species whorls and teeth.
(A) Edestus minor represented by associated upper and lower whorl. (B) Edestus triserratus adult represented by two separate specimens of compatible size, and subadult represented by associated upper and lower whorls. (C) Edestus heinrichi adult form represented by two separate specimens of compatible size, and subadult represented by associated upper and lower whorls. (D) Edestus vorax adult upper whorl and lower tooth of separate individual. Scale bar for all specimens.
Fig 10.
Edestus heinrichi preying on a palaeoniscoid fish.
3D illustration by Jesse Pruitt and Evelyn Vollmer, Idaho Virtualization Lab.
Fig 11.
Lestrodus and Edestus in space and time.
Paleogeographic map for the Middle Pennsylvanian modified from [43] and sea level curve modified from [44]. Uncertainty in species range shown with dashed boxes. Abbreviations: Kasim. = Kasimovian; vorax = Edestus vorax; hein. = Edestus heinrichi; minor = Edestus minor; tri. = Edestus triserratus.