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Fig. 11 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 11. SEM photographs of the pits on the craspeditid ammonite Kachpurites fulgens (Trautschold, 1861) shells from the Late Volgian, Kachpurites fulgens Zone, Eganovo (A) and Mnevniki (B) localities, Moscow region, Central Russia. A. MSU 118/1. Transverse (A1, A2) and longitudinal (A3, A4) cross-sections of the shell layers in the pit area. The bending of shell wall inside the pit is clearly visible. B. MSU 118/9. The phosphatic mineral inside the pit (B1) and the tubercle (reflection of the pit) (B2) located on the dorsal side of the specimen.

Fig. 10 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 10. The pits on the aragonitic shell layers of the craspeditid ammonite Kachpurites fulgens (Trautschold, 1861) from the Late Volgian, Kachpurites fulgens Zone, Mnevniki, Moscow region, Central Russia; MSU 118/10. A. Body chamber with slightly dissolved shell layers. General view in ventro-lateral (A1), ventral (A2), and dorsal (A3) views; on the dorsal side the small tubercle is visible, which reflect the pit on the previous whorl. B. Two pits on the specimen, SEM photograph. C. Two pits on the specimen, optical binocular microscope photographs.

Fig. 6 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 6. Craspeditid ammonite Kachpurites fulgens (Trautschold, 1861) from the Late Volgian, Kachpurites fulgens Zone, Moscow region, Eganovo locality, Central Russia; shell with pits and deformed growth lines, MSU 118/1. A. General lateral view. B. Dorsal view, two tubercles located on the dorsal side of the body chamber, reflecting pits which are located on the previous shell whorl. C. The pits and deformed growth lines, which are related with pits, on the lateral surface of the specimen. D. Outer shell layer with phosphatic mineral inside pits and curved growth lines connected with these pits. Photographs (A, B, C1, D1), explanatory drawings (C2, D2).

Fig. 9 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 9. Craspeditid ammonites Kachpurites fulgens (Trautschold, 1861) from the Late Volgian, Kachpurites fulgens Zone, Moscow region, Central Russia, Eganovo (A, B) and Mnevniki (C, D) localities; shells with pits and epizoans, lateral (A1, B1, C, D) and dorsal (A2, B2) views. A. MSU 118/7, abnormal " scaphitoid" shell shape. There are several pits on the ventral side of the shell (A2). B. MSU 118/16, fragment of the abnormal shell. The fragment of bivalve shell which caused distortion of the shell growth can be seen on the dorsal side (B2). There are no pits on this specimen. C. MSU 118/8, body chamber with pits on both sides of the shell. D. MSU 118/9, fragment of the body chamber with pits, many of them are merged with each other.

Fig. 7 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 7. The pits with preserved phosphatic remnants on the shell of craspeditid ammonite Kachpurites fulgens (Trautschold, 1861) from the Late Volgian, Kachpurites fulgens Zone, Moscow region, Eganovo locality, Central Russia; MSU 118/1. A, B. Three pits with phosphatic filling on the well-preserved surface of the specimen. C, D. Transverse cross-sections of the two pits with phosphatic remnants located on the well-preserved part of the shell of the specimen. Note the thin outer prismatic and thick nacreous layers. The photos were taken using an optical binocular microscope.

Fig. 5 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 5. Craspeditid ammonite Kachpurites fulgens (Trautschold, 1861) from the Late Volgian, Kachpurites fulgens Zone, Moscow region, Eganovo locality, Central Russia; shell structure and chemical composition of the filling of pits, MSU 118/1. A, B. Aragonite layer of the shell. C. EDS (Energy Dispersive X-ray Spectroscopy) analysis of the brown mineral in the pit on the surface of specimen (asterisk in B).

Fig. 8 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 8. Craspeditid ammonites Kachpurites fulgens (Trautschold, 1861) from the Late Volgian, Kachpurites fulgens Zone, Moscow region, Central Russia, Mnevniki (A) and Eganovo (B−E) locality; shells with pits. A. MSU 118/2, fully preserved body chamber with pits, which are clearly visible not far from the aperture; lateral view. B. MSU 118/3, shell with abnormal constriction on the body chamber; in ventral (B1) and lateral (B2) views. C. MSU 118/4, shell with fully preserved body chamber; in lateral (C1) and ventral (C2) views. There are abnormally small lateral attachment scars (on the top of the C1) and pits on the apertural part of the shell. D. MSU 118/5, shell without aperture and with pits which are located ventro-laterally; lateral view. E. MSU 118/6, body chamber fragment without aperture and phragmocone; ventral view (E1), enlarged view of the pit (E2). There is only one relatively large pit on this fragment.

Fig. 12 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 12. Clusters of pits on the surface of the craspeditid ammonite Kachpurites fulgens (Trautschold, 1861) shell from the Late Volgian, Kachpurites fulgens Zone, Eganovo ocality, Moscow region, Central Russia, MSU 118/1. A. General view, three clusters which repeatedly occurred on the shell marked by lines: ventro-lateral and dorso-lateral clusters marked by dotted line, mid-lateral cluster marked by solid line. B. Two groups of pits on the anterior ventro-lateral portion of the shell. They are very similar to each other and likely were formed by the same epizoans during the subsequent stages of shell growth.

Fig. 3 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 3. Upper Volgian strata in Eganovo locality. Three subzones of Kachpurites fulgens Zone. The thickness of all layers is about 1.4 m. The traces on the surface of the layer have been left by the excavation knife.

Fig. 2 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 2. Stratigraphic column of the localities. A. Mnevniki, Moscow. B. Eganovo, Moscow area. The braces mark the horizon from which the described ammonites have been collected. Ammonite zones (see Rogov and Starodubtseva 2014). The total thickness of the layers is about 2 m.

Fig. 4 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 4. The circular diagram of the frequency of the genera distribution in Kachpurites fulgens Zone.

Fig. 1 in A new type of shell malformation caused by epizoans in Late Jurassic ammonites from Central Russia

Fig. 1. Map of Moscow area with localities: 1, Eganovo (55°32'08.28" N; 38°03'10.47" E); 2, Mnevniki (55°46'4.12" N; 37°28'4.67" E).

Fig. 9 in Form and formation of flares and parabolae based on new observations of the internal shell structure in lytoceratid and perisphinctid ammonoids

Fig. 9. Transition of parabolae and flares in Analytoceras hermanni (Gümbel, 1868) (BSPG Man-x) from Bihati river valley south of Baun, SW Timor, Hettangian, Jurassic (compare Hoffmann and Keupp 2010); in ventral (A) and lateral (B) views.

Fig. 8 in Form and formation of flares and parabolae based on new observations of the internal shell structure in lytoceratid and perisphinctid ammonoids

Fig. 8. Internal structure of parabolae (transversal section) in Choffatia sp. (BSPG MAn-4519) from Dubki near Saratov, SW Russia; Upper Callovian, Jurassic. A. Parabola with notches. B–E. Discontinuity of the parabolae, the primary shell forms slots at the position of the notches. A secondary shell is attached from beneath. The relief is compensated by the dorsal inner prismatic layer. Abbreviations: apc, apertural prismatic coating; dipl, dorsal inner prismatic layer; ipl, inner prismatic layer; ncl 1/2, nacreous layer of the primary/secondary shell.

Fig. 7 in Form and formation of flares and parabolae based on new observations of the internal shell structure in lytoceratid and perisphinctid ammonoids

Fig. 7. Internal structure of parabolae (median section, growth direction right) in Choffatia sp. (BSPG MAn-4520) from Dubki near Saratov, SW Russia; Upper Callovian, Jurassic. A, B. Discontinuity of the parabola, the primary nacreous layer ends abruptly. A secondary nacreous layer is attached from beneath. The relief is compensated by the dorsal inner prismatic layer. C. Discontinuity of parabolae at the position of the notches. The primary shell bends outwards and has an apertural prismatic coating. The secondary shell is attached from beneath. In front of the free edge of the primary shell a symmetric, prismatic thickening is formed. The dorsal shell compensates the relief. D. Lateral parts of the notches show the typical outward undulation of the new shell of the parabolic node. Abbreviations: apc, apertural prismatic coating; dipl, dorsal inner prismatic layer; dncl, dorsal nacreous layer; dopl, dorsal outer prismatic layer; ncl 1/2, nacreous layer of the primary/secondary shell; opl 1/2, outer prismatic layer of the primary/secondary shell; pt, prismatic thickening; S, septum.

Fig. 6 in Form and formation of flares and parabolae based on new observations of the internal shell structure in lytoceratid and perisphinctid ammonoids

Fig. 6. Internal structure of a secondary flare (median section, growth direction right) in Argonauticeras besairiei Collignon, 1949 (BSPG MAo- 1802) from Ambatolafia, Mahajanga Basin, NW Madagascar; Lower Albian, Cretaceous. Abbreviations: apc, apertural prismatic coating; dipl, dorsal inner prismatic layer; ipl, inner prismatic layer; ncl 1/2, nacreous layer of the primary/secondary shell; opl 1/2, outer prismatic layer of the primary/secondary shell; sb, shell bulge.

Fig. 2 in Form and formation of flares and parabolae based on new observations of the internal shell structure in lytoceratid and perisphinctid ammonoids

Fig. 2. Internal structure of flares (median section, growth direction right) in Argonauticeras besairiei Collignon, 1949 (BSPG MAo-1801) from Ambatolafia, Mahajanga Basin, NW Madagascar; Lower Albian, Cretaceous. A. Complete flare, the primary shell bends outwards and forms a frill. The flare ends in a backward reflection of the shell, i.e., apertural margin. Secondary shell material is attached from beneath and forms a prominent bulge in front of the flare. B. Close-up of A, contact of the primary shell and the secondary shell. The interior of the flares is covered by an apertural prismatic coating. C. Apertural margin of the flare, the primary shell wedges out. The primary outer prismatic layer and the apertural prismatic coating form a vanishing prismatic wedge. Abbreviations: apc, apertural prismatic coating; dipl, dorsal inner prismatic layer; ipl, inner prismatic layer; ncl 1/2, nacreous layer of the primary/secondary shell; opl 1/2, outer prismatic layer of the primary/secondary shell; sb, shell bulge; var, varix.

Fig. 5 in Form and formation of flares and parabolae based on new observations of the internal shell structure in lytoceratid and perisphinctid ammonoids

Fig. 5. Resorption process in flares of Lytoceratoidea. A. A complete flare with mantle cover. B. The retracting mantle begins resorption of shell material at the base of the flare. C. The mantle tissue rounds the flare stump through resorption. D. The retracted mantle begins secretion of secondary shell material. E. The mantle continues secreting the secondary shell. F. The mantle of the subsequent whorl begins to overgrow the flare stump of the preceding whorl. G. The mantle of the subsequent whorl overgrows the complete flare of the preceding whorl and begins its resorption. H. The mantle of the subsequent whorl resorbs the flare stump of the preceding whorl. I. The mantle of the subsequent whorl has smoothed the shell surface of the preceding whorl.

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Fig. 9 in Unusual shell anatomy and osteohistology in a new Late Cretaceous panchelid turtle from northwestern Patagonia, Argentina

Fig. 9. Strict consensus tree from the four MPT's obtained from the morphological cladistic analysis of Rionegrochelys caldieroi gen. et sp. nov. The stars show the alternative positions of Pseudemydura umbrina. The numbers in the left of the lines are Bremer support values, whereas the numbers in the right of the lines are Jackknife and Bootstrap support values, respectively, that exceed 50%. Abbreviations: Af, Africa, SAm, South America, NAm, North America, Au, Australia; l-n, long-necked panchelids, s-n, short-necked panchelids.