Such conditions in the earliest stages of post mortem development of lingulate valves are confirmed by the typical dark colour and high pyrite content (detected by the X-ray diffraction method) of U.
Shell mineralogy of the lingulate brachiopods from the Baltic "Obolus phosphorite".
The terminology used in describing baculate shell structures in lingulate brachiopods stems from Holmer (1989) and Cusack et al.
The nanofibrils are relevant structural units in the hierarchical structure of lingulate brachiopods with baculate shell structure.
Apatite varieties in the shell of a Cambrian lingulate
brachiopod Obolus apollinis Eichwald.
1995) and, possibly, with specific diagenetic alteration conditions, but it is not usual in Recent or fossil lingulate brachiopod shells.
Evidence from XRD studies and chemical analyses has supported the presence of hydroxyl ion in Recent lingulate brachiopod shells, where it has lattice parameter intervals a = 9.38-9.40 [Angstrom] and c = 6.86-6.88 [Angstrom] (Puura & Nemliher 2001).
brachiopods from Lower Ordovician (Tremadoc) chalcedonites, Holy Cross Mountains, Poland.
Comparison of the data in Table 1 with those published on fossil lingulates
(Ushatinskaya et al.
Leaves densely rosulate, spreading, coriaceous, 40-60 cm long; leaf sheaths elliptic, 8-12 x 6-10 cm, somewhat nerved, densely appressed brown-lepidote especially abaxially, dark castaneous at the base abaxially; leaf blades lingulate
, broadly acute, apiculate, 3-4 cm wide, somewhat nerved, appressed pale punctate-lepidote, especially abaxially, light to dark green.
90[degrees] from the axis, thin-coriaceous, 5-40 cm long with an ovate partially castaneous sheath, 2-5 x 3-5 cm and with a lingulate
acute blade 2-4 cm wide; the lowest bright green, the upper pale green proximally, bright pink distally or entirely bright pink; all appressed punctate-lepidote and nerved; branches polystichously arranged, 10-12 mm apart, each with a stout 1-3 mm long peduncle, spreading at ca.
The occurrences of Hunneberg-Billingen lingulates
(Puura 1996) also point to elevated P in seawater of that time.