Fig 1.
Locations of the presently studied sites (see Table 1 for details).
Table 1.
Sample information, sample size, stratigraphy, palaeo-water depth and atelostomate spines and fragments recovered.
Details on the respective expedition and drillcores, including data on the palaeo-water depths, can be obtained from the homepage of the International Ocean Discovery Program, IODP (https://www.iodp.org/). Colour code for Tabs. 1 and 2: dark green: Lower Cretaceous, light green: Upper Cretaceous, orange: Cenozoic.
Fig 2.
Key morphological features of atelostomate spines.
a, b) Aceste bellidifera Thomson, 1877 (coast off Liberia, Atlantic), showing the various spine morphologies and size ranges in relation to their functions on the echinoids’ test. a) apical side, b) adapical side (length: ca. 15 mm, photo: C. Neumann, Berlin), c-f: morphological features of atelostomate spines. c) general overview (lower Miocene of Newfoundland, Site U1407, unknown species), d) cross section through a spine of Brissus obesus Verril, 1867 showing the wedges, bridges and the lumen/cylinder, e) longitudinal section through a spine of Ceratophysa rosea (A. Agassiz, 1879), showing the horizontally arranged pores typical of the Holasteroida, f) longitudinal section through a spine of Eurypatagus parvituberculatus (Clark, 1924), showing the helicoidal pore orientation in the cylinder, typical of the Spatangoida.
Fig 3.
Examples of Aptian to Eocene deep-sea atelostomate spine morphologies.
a, b) Sample 1049C-12X-4W, 138–139 cm (Aptian), c, d) Sample U1407C-28X-CCW (Albian), e: Sample U1407C-27X-2W, 50–51 cm (Cenomanian) f, g: Sample U1407A-27X-5A, 60–61 cm (Cenomanian), h-j) Sample U1407C-25H-CCW (Coniacian-Santonian), k) Sample 690C-19X-2W (Campanian), l-n) Sample U1407-C-20H-CC (Maastrichtian), o) Sample U1407C-17H-CC (Paleocene), p, q, r) Sample U1407C-15H-CC (Paleocene), s) Sample U1407C-5H-CC (Eocene), t) Sample U1407C-7H-CC (Eocene), u, v) Sample U1407C-5H-CC (Eocene). Scale bar: ca. 100 μm (except n: scale bar 50 μm).
Fig 4.
Examples of Oligocene to Pleistocene deep-sea atelostomate spine morphologies.
a) Sample U1334C-16H-3W, 148–150 cm (Oligocene), b) Sample U1334C-12H-4W, 43–45 cm (Oligocene), c) 689D-6H-4W, 52–54 cm (Oligocene), d) massive spatangoid spine with acute tip, exposing the spatangoid-like perforation in the cylinder (height: 2.3mm), Sample U1334C-16H-3W, 148–150 cm (Oligocene), e) Sample U1334C-16H-3W, 148–150 cm (Oligocene), f) Sample U1334C-12H-5W, 115–118 cm (Oligocene), g) Sample 689D-6H-4W, 52–54 cm (Oligocene), h-j) Sample U1405B-13H-4W, 40–41 cm (Miocene), k) massive spatangoid spine fragment (length ca. 2 mm), Sample U1405B-13H-4W, 40–41 cm (Miocene), l-n) Sample U1405B-13H-4W, 37–38 cm (Miocene), o-q) Sample 849D-8H-2W, 126–128 cm (Pliocene), r-t) Sample U1407A-1H-CC (Pleistocene). Scale bar, if not stated otherwise, ca. 100 μm.
Fig 5.
Morphological inventory of atelostomate spine tips and characteristic shaft fragments in the terminal Maastrichtian and early Paleocene, exemplified by Expedition 342 sites U1407 and U1403 (Newfoundland, see Fig 1 and Table 1). Specimens are scaled to similar sizes to illustrate their morphological variability. Actual sizes are given in height (h).
a) Sample U1407C-20H-CC (h: 0.88 mm), Maastrichtian, b) Sample U1407C-20H-CC (h: 0.97 mm), Maastrichtian, c) Sample U1407C-20H-CC (h: 1.20 mm), Maastrichtian, d) Sample U1407C-20H-CC (h: 0.80 mm), Maastrichtian, e) Sample U1407C-20H-CC (h: 0.85 mm), Maastrichtian, f) Sample U1403B-28X-2W, 70–72 cm (h: 1.03 mm); g) h: 0.42 mm, h) Sample U1403B-28X-2W, 70–71 cm (h: 0.86 mm), i) Sample U1403B-28X-2W, 76–78 cm (h: 0.55 mm), Maastrichtian, j) Sample U1403B, 28X-2W, 76–78 cm (h: 0.50 mm), Maastrichtian, k) Sample U1407C-20H-CC (h: 0.75 mm), Maastrichtian, l) Sample U1407C-20H-CC (h: 1.09 mm), Maastrichtian, m) Sample U1407C-19H-CC (h: 0.78mm), early Paleocene, n) Sample 1407C-19H-CC (h: 0.69 mm), early Paleocene, o) Sample 1407C-19H-CC (h: 0.54 mm), early Paleocene, p) Sample 1407C-19H-CC (h: 0.55 mm), early Paleocene.
Table 2.
Stratigraphic position of samples used to calculate the atelostomate spine accumulation rate (ASAR), including approximate age in Ma, spines per gram sediment (sp/g), the linear sedimentation rate (LSR) and dry bulk density (DBD).
For sets of samples, mean values for age and ASAR were calculated, and minima and maxima are given under remarks (comp. also “Material and Methods”). Cen./Turon.: Cenomanian/Turonian boundary interval, Coniac.: Coniacian, Santon.: Santonian, Campan.: Campanian, Maastricht.: Maastrichtian (see “Supplementary Information” for data of sets of samples).
Fig 6.
Box plot of atelostomate spine diameters across the K-Pg boundary event (Maastrichtian: Sample U1407-20H-CC, Paleocene: Sample U1407C-19H-CC) (with minima, maxima, median and the 25–75 percent quartiles; see S1 Table).
Outliers are shown as circles and stars, respectively; outside the inner fences as circles, beyond the outer fences as stars.
Fig 7.
The Atelostomate Spine Accumulation Rate, ASAR (spines/cm-2 kyr-1), from the terminal early Cretaceous to the Pleistocene (ca. 104 Ma) as a proxy for deep-sea Atelostomata biomass.
Abbreviations (following [57, 81]): OAE 2: Oceanic Anoxic Event 2, K-Pg Boundary Event: Cretaceous-Paleogene Boundary Event, PETM: Paleocene-Eocene Thermal Maximum, EECO: Early Eocene Climate Optimum, MECO: Middle Eocene Climatic Optimum, EOT: Eocene/Oligocene Transition, LOW: Late Oligocene Warming, MMCO: Mid-Miocene Climatic Optimum.