Paleontología Mexicana

The genus Zuercherella Casey, 1954 in the Upper Aptian (Lower Cretaceous) of the Cottonwood District, Northern California

El género Zuercherella Casey, 1954 en el Aptiano superior (Cretácico Inferior) del Distrito de Cottonwood, en el norte de California

Latil, Jean-Louis1,*; Murphy, Michael A.2; Rodda, Peter U.3

1 G.R.E.G.B., 95 chemin de Galachanne, Le Maupas, 05300 Lazer, France.

2 University of California, Riverside, USA.

3 California Academy of Sciences, San Francisco and University of Oregon, Eugene, USA.

*g.r.e.g.b@wanadoo.fr

Abstract

The presence of the Tethyan species Zuercherella zuercheri (Jacob, 1906) in the Upper Aptian of the Cottonwood district, northern California, is documented for the first time, allowing confirmation of an affinity between the Tethyan and Northeast Pacific biota during the Upper Aptian, Eotetragonites wintunius and Acanthohoplites gardneri Zones. The paleontological study of very well-preserved material also allows a better knowledge of the adult morphology of Zuercherella zuercheri.

Keywords: Ammonites, Aptian, California, Cretaceous, Paleobiogeography.

Resumen

Se reporta por primera vez la presencia de la especie tetisiana Zuercherella zuercheri (Jacob, 1906) en el Aptiano superior del distrito de Cottonwood, en el norte de California, lo que permite confirmar la existencia de afinidades entre la biota tetisiana y la del Pacífico nororiental durante el Aptiano superior, en las biozonas Eotetragonites wintunius y Acanthohoplites gardneri. El estudio paleontológico de material muy bien conservado también permite tener un mejor conocimiento de la morfología del adulto de Zuercherella zuercheri.

Palabras clave: Cretácico, Ammonites, Aptiano, California, Paleobiogeografía.

1. Introduction

The upper Aptian ammonite fauna of northern California has been long recognized for its endemism (Anderson, 1902, 1938; Murphy, 1956, 1967a and b; Amédro and Robaszynski, 2005; Murphy and Rodda, 2006; Rodda and Murphy, 2022).

Zuercherella zuercheri (Jacob, 1906), a distinctive species known from South America, and Europe, and reported here for the first time in western north America, allows us to highlight a connection between the Tethys and the Northeast Pacific Province during the lower part of Upper Aptian.

Most of the material herein investigated has been collected in the 1950’ by one of us (M.A.M.) in the Upper Aptian of northern California, Eotetragonites wintunius Zone and base of the Acanthohoplites gardneri Zone. These specimens were previously identified as Puzosia sp. A and/or P. sp. B in Murphy (1956).

1. Systematic paleontology

Conventions. Dimensions are given in millimeters: D = diameter; W = whorl breadth; H = whorl height; U = umbilicus.

We follow the descriptive categories established by Rodda and Murphy (2022).

Abbreviations used.

• CASG - California Academy of Sciences, Geology Collection.
• UCLA - University of California, Los Angeles.
• UJF-ID - Université Grenoble-Alpes, ex Institut Dolomieu collections.

Order Ammonitida Zittel, 1884

Suborder Ammonitina Hyatt, 1889

Superfamily Desmoceratoidea Zittel, 1895

Family Desmoceratidae Zittel, 1895

Subfamily: Uhligellinae Latil, Murphy and Rodda, 2023

Definition of the subfamily. The subfamily Uhligellinae, as herein understood, is probably polyphyletic and brings together the genera Zuercherella Casey, 1954, Uhligella Jacob, 1907, Pseudorbulites Casey, 1961, Grantziceras Imlay, 1961, Roberticeras Latil, Murphy and Rodda, 2023, Leconteites Casey, 1954, Brewericeras Casey, 1954, and provisionally Boliteceras Whitehouse, 1928 and Cophinoceras Whitehouse, 1928. This subfamily comprises constricted desmoceratids that derive from the genera Zuercherella and Pseudorbulites with a suture line with symmetrical to feebly asymmetrical, trifid L. We do not follow Wright (1996) and maintain the genera Leconteites and Brewericeras within the Uhligellinae because of their symmetrically trifid suture.

Discussion. The genus Uhligella has been extensively discussed by Riccardi and Medina (2002, p. 306) who follow the Treatise classification.

The genus Pseudorbulites Casey, 1961 (type species: Desmoceras (Uhligella) convergens Jacob, 1908, p. 29, pl. 2, figs. 24–26, by the original designation of Casey, 1961, p. 145) was considered by Wright (in Wright et al., 1996, p. 81) as a possible synonym of Beudanticeras (Grantziceras) Imlay, 1961, without any discussion. Kennedy (2000, p. 165) regarded it as a synonym of Beudanticeras s.s., considering that Jacob’s species differs little from early Roberticeras. As pointed out by Riccardi and Medina (2002, p. 298), Pseudorbulites and Grantziceras have both a stout section and funnel-shaped umbilicus, but Grantziceras differs from Pseudorbulites by its less involute coiling, more numerous strongly biconcave constrictions and its rather broader ventral area. In spite of that, Riccardi and Medina considered that Pseudorbulites and Grantziceras were probable synonyms. We agree with Casey (1961, p. 145) statement: ‘I am of the opinion that Pseudorbulites should be established as an independant genus rather than as a subgenus of Beudanticeras. The outstanding features of Pseudorbulites are its stout, elliptical whorls, funnel-shape umbilicus, striated test and highly dissected suture-line.’ Furthermore, Grantziceras is a typical pacific boreal genus of a rather elevated Lower Albian age (Brewericeras hulenense Zone). Because of its stratigraphic range just below and above the Aptian-Albian boundary, and because of its tethyan origin, Pseudorbulites is regarded herein as a distinct genus and as a possible ancestor of the Lower-basal Middle Albian tethyan lineage Roberticeras africana (Pervinquière, 1907), R. dupinianum d’Orbigny, 1841, R. arduennense Breistroffer, 1947 and the still enigmatic R. subparandieri Spath, 1923.

The genus Boliteceras, a rather involute, with funnel-shaped umbilicus, and inflated ammonite, with broad, shallow, sinuous constrictions, fine, feeble ribs and broadly rounded venter, is in need of further study. The suture, not figured, is said to have wide-stemmed saddles and regularly trifid first lateral lobe. This genus has been regarded as a doubtful genus by Wright (1996) without further explanation. Riccardi and Medina (2002) regarded it as a synonym of Beudanticeras (now Roberticeras). Whitehouse (1928) assigned an Upper Albian age to the genus Boliteceras on the basis of the occurrence of Upper Albian ammonites within the same formation. Both Boliteceras daintreei (Etheridge, 1872) and Boliteceras perlatum (Whitehouse, 1928) are known from Hughenden, Queensland, Wallumbilla Formation and possibly Allaru Mudstone (Rozefelds et al., 1990). The Wallumbilla Formation has been redefined by Vine et al. (1967) and Gray et al. (2002) and both authors give it an Aptian to Albian age. The Allaru Mudstone, doubtfully considered as a lateral equivalent of the Oodnadatta Formation, is probably Albian-Cenomanian (Gray et al., 2002). According to Day (1968) Boliteceras daintreei co-occurs with ?Falciferella and is of Lower Albian age while McKenzie (personal communication) gives a Middle Albian age. The genus Boliteceras is herein excluded from the synonymy of the genus Roberticeras and, pending a revision of the australian material, Boliteceras is herein considered as a distinct genus and provisionally maintained in the Uhligellinae.

The monospecific genus Cophinoceras was created for Upper Albian ammonites (Tambo series) of eastern Australia, with elliptical whorl section, narrow funnel shape umbilicus, straight prorsiradiate primary ribs (constrictions covered by the test), each pair of such ribs being separated by 8–12 short straight intercalatories. The suture is said to have wide-stemmed saddles and regularly trifid first lateral lobe. C. ogilviei has been collected near the mouth of Bynoe River, on Normanton-Burketown Road, N Queensland, Autralia, in the Normanton Formation which is considered Albian and more recently Cenomanian (Rawlings et al., 1997). According to Day (1968), this species comes from the Upper Albian.

Day (1968, unpublished dissertation) described a new Upper Albian species: ‘’Beudanticeras’’ vinei, for several large ammonites, saying that it could be referred to Cophinoceras. He adds: «“Beudanticeras’’ vinei sp. nov. is referred to the genus Beudanticeras with some reservation. The species attains an exceptionally large size for a Beudanciceras and approaches the dimensions of many species of Puzosia Bayle. However, typical Puzosia has a more depressed whorl section. The deep ventral lobe of the suture is also unusual for a Beudanciceras. The suture of Desmoceras Zittel is very similar, but that form also has a depressed whorl section. ». This species co-occurs with Myloceras, Labeceras and Appurdiceras and is of Late Albian age.

In our opinion, «Beudanticeras» vinei probably represents the adult stages of Cophinoceras ogilviei. The taxonomic position of the genus Cophinoceras remains uncertain but is in no way related to the european Lower Albian Roberticeras. As for Boliteceras, it is provisionally maintained within the Uhligellinae, keeping in mind that it seems to be more closely related to the Puzosiinae.

Genus Zuercherella Casey, 1954

(= Corteziceras Etayo Serna, 1979, p. 27; type species C. cortezi by original designation)

Type species. Desmoceras zuercheri Jacob, 1906, p. 9, by the original designation of Casey, 1954, p. 112.

Diagnosis. Medium-sized high-whorled shell with oval or subquadrate whorl-section, venter narrowly rounded; constrictions shallow, sinuous; between the constrictions are several ribs. Main ribs begin slightly above or at the umbilical rim; intercalatory ribs occur only in the upper half of the flanks. Outer whorls appear to be feebly ornamented based on a single specimen.

Zuercherella zuercheri (Jacob 1906)

Figures 2a–d, 3a–c, 4a-c, 5, 6

Synonymy.

1906 Desmoceras zürcheri Jacob, p. 9, pl. II, fig. 1–3.

?1907 Desmoceras (Uhligella) cf. zürcheri Jacob;

Pervinquière, p. 137, pl. 5, fig. 26.

1910 Uhligella zürcheri Jacob and Tobler; Kilian,

pl. 10, fig. 3.

1920 Uhligella zürcheri Jacob and Tobler; Fallot,

p. 261, pl. 3, fig. 7.

Non 1933 Uhligella zuercheri Jacob and Tobler;

Rouchadze, p. 183, pl. 2, fig. 4, 5.

1949 Uhligella zürcheri Jacob; Luppov et al., p. 211,

pl. LX, fig. 1a, 1b, text-fig. 37.

1954 Zuercherella zuercheri (Jacob and Tobler);

Casey, p. 112.

1956 Puzosia sp. A; Murphy, fig. 6.

1956 Puzosia sp. B; Murphy, fig. 6.

1957 Zurcherella zurcheri Jacob; Wright p. L368,

fig. 481: 1a, b.

1958 Zürcherella zürcheri Jacob; Luppov and

Drushchits, p. 109, pl. 50, fig. 8.

?1964 Zürcherella zürcheri (Jacob); Fülöp, pl. 4,

fig. 1, 2.

1964 Zürcherella zürcheri Jacob; Kemper, p. 39, pl. 4,

fig. 1; pl. 15, fig. 1; pl. 17, figs 1–3.

1966 Zürcherella zürcheri (Jacob); Schindewolf,

p. 623.

1968 Beudanticeras (Zuercherella) zuercheri (Jacob);

Wiedmann and Dieni, p. 130, pl. 12, fig. 1.

1969 Zurcherella zurcheri Jacob; Egoian, p. 177, pl. 15,

fig. 8, 9; pl. 25, fig. 64.

1971 Zuercherella zuercheri Jacob; Kvantaliani, p. 98,

pl. 15, fig. 1.

1971a Zürcherella zürcheri (Jacob); Kemper, pl. 4,

fig. 7.

1971b Zürcherella zürcheri (Jacob); Kemper, pl. 29,

fig. 1.

1976 Zürcherella zürcheri (Jacob); Kemper, pl. 4,

fig. 7.

1980 Zurcherella zurcheri (Jacob); Thomel, p. 124,

fig. 246.

1982 Beudanticeras (‘‘Zuercherella’’) zuercheri (Jacob);

Renz, p. 22, pl. 1, fig. 20; text-fig. 10c, d.

?1986 Zurcherella alpina Demay and Thomel, p. 34.

1993 Zuercherella zuercheri (Jacob); Sharikadze,

p. 135,

text-fig. 6.

1995 Zürcherella zürcheri Jacob; Kemper, pl. 5, fig. 5.

1996 Zuercherella zuercheri (Jacob); Wright, p. 80,

fig. 61: 2.

1996 Zuercherella zuercheri (Jacob); Mutterlose, p. 51,

pl. 3, fig, 2, 3.

1996 Zürcherella zürcheri (Jacob); Weber, p. 79, pl. 3,

fig. 1, 2, pl. 8, fig. 2, 3, pl. 9, fig. 4.

? 2004 Zuercherella cf. zuercheri (Jacob and Tobler,

1906); Bogdanova and Hoedemaeker, p. 245,

pl. 41, fig. 2.

2005 Zuercherella zuercheri (Jacob and Tobler);

Dutour, pl. 17, fig. 1-6, fig. 12.

2005 Zuercherella zuercheri (Jacob); Kvantaliani in

Kotetishvili et al., p. 322, pl. 61, fig. 2.

? 2007 Zuercherella zuercheri Jacob et Тоblег; Szives,

p. 55, pl. 3, figs 21, 22, 23.

2008 Zurcherella zurcheri (Jacob & Tobler); Joly &

Delamette, fig. 6L.

2011 Zuercherella zuercheri (Jacob); Klein and Vašiček,

p. 113 (pars).

Type material. The species is based on four syntypes, juveniles, less than 50 mm of diameter. Two of the four syntypes are in the collections of the University Grenobles Alpes (ex Dolomieu collections), both from the Upper Aptian of Chaudon (Alpes de Haute Provence, France). We were unable to trace the syntypes figured by Jacob (1906, pl. 2, fig. 1 and text-fig. 3) from the Upper Aptien of Luitere Zug (Switzerland). No type specimen was designated by Jacob. Dutour (2005, unpublished) considers the specimen figured by Jacob (1906, pl. 2, fig. 1) as the holotype. Consequently, the specimen figured by Jacob (pl. 2, fig. 3) is herein selected as the lectotype. The lectotype UJF-ID.1064 Desmoceras (Uhligella) zürcheri Jacob, 1906, pl. 2, fig. 3, is herein refigured (Fig. 2a, b).

N°	D	H	W	U	W/H
UJF-ID.1064	39.0	18.0 (.46)	12.7 (.33)	7.8 (.20)	0.71

UJF-ID.1064 is a juvenile preserved as a pyritized internal mold. The coiling is involute (U/D = 0.20) with low, broadly convex umbilical wall and shoulder, feebly convex flanks, and narrow feebly convex venter. There are seven radial, feebly flexuous constrictions on the last half-whorl, with adapical rib on the outer part of the flanks and venter. There are about six feeble, fine riblets between each constriction, that arise on the inner third of the flanks. The suture shows a trifid, symmetrical L (Fig. 2d).

UJF-ID.1065 Desmoceras (Uhligella) zürcheri Jacob, 1906, pl. 2, fig. 2 : paralectotype

N°	D	H	W	U	W/H
UJF-ID.1065	43.0	19.0 (.44)	14.5 (.34)	10.5 (.24)	0.76

An oxidized limonitic juvenile specimen, differing only from the previous specimen by its flatter flanks. 

The original figure of one of the syntypes from Luitere Zug (Jacob, 1906, pl. 2, fig. 1) is herein refigured (Fig. 2c), showing the differences of ornamentation owing to the kind of preservation.

Material. Eight specimens from Northern California:

• CASG70778 of unknown origin (Figs 5, 6);
• CASG70779 (UCLA loc. 2845, = M62: 40°27’30.91”N, 122°35’47.96W): Acanthohoplites gardneri Zone (Figs 4a-c);
• CASG70781 (including CAS70784: UCLA loc. 2867, = M85: 40°27’51.16”N, 122°34’13.61W): from Huling Creek, co-occurs with ‘Acanthohoplites’ aegis at the base of the Acanthohoplites gardneri Zone;
• CASG70783 (UCLA loc. 2856, = M74: 40°27’57.73”N, 122°36’45.15W), from North Fork of Cottonwood Creek, where it co-occurs with Acanthohoplites gardneri at the base of the Acanthohoplites gardneri Zone (Figs 3a–c);
• CASG70784 (UCLA loc. 2868, = M86: 40°27’55.79”N, 122°34’30.11W): from Huling Creek section, where it co-occurs with Eotetragonites wintunius (Anderson, 1938), Eotetragonites wintunius Zone;
• CASG70785 of unknown origin;
• an unnumbered specimen (loc. M135: 40°25’23.87”N, 122°39’13.78W), from the Bald Hills, Barr section where it co-occurs with Eotetragonites wintunius (Anderson, 1938), Melchiorites indigenes (Anderson, 1938), Hypophylloceras onoense (Stanton, 1895) and Argonauticeras argonautarum (Anderson, 1902), Eotetragonites wintunius Zone;
• an unnumbered specimen of unknown origin.

These specimens have been collected within the Eotetragonites wintunius Zone and at the base of the Acanthohoplites gardneri Zone, Upper Aptian of Shasta Co, California (Murphy, 1956). They are preserved as calcareous internal molds, partially covered by aragonitic shell.

N°	D	H	W	U	W/H
Unnumbered	38.5	18.0 (.47)	14.5 (.38)	8.5 (.22)	0.81
CASG70781	44.0	19.5 (.44)	15.0 (.34)	8.5 (.19)	0.77
M135	54.5	23.5 (.43)	21.0 (.39)	15.0 (.28)	0.89
CASG70783	80.0	34.0 (.43)	26.5 (.33)	20.0 (.25)	0.78
CASG70779	98.5	41.0 (.42)	33.5 (.34)	28.5 (.29)	0.82

The coiling is involute on the juvenile (U/D between 0.19 and 0.22), becoming moderately involute with age with (U/D between 0.25 and 0.29). The whorl section is compressed (W/H between 0.77 and 0.89), oval to elliptical, with funnel-shape, moderately deep umbilical wall, broadly rounded umbilical shoulder, slightly convex flanks, with a maximum of width at the inner third. The outer part of the flanks converge to a narrowly rounded venter. The inner whorls, up to a diameter of 30 mm, show inconspicuous coarse ribs on the outer part of the flanks of the internal mold, and numerous falcoid growth lines on the shell that are strongly prorsiradiate on the inner part of the flanks. Beyond 30 mm, there are 9–10 prorsiradiate, coarse, wide, shallow constrictions, that are slightly projected forward on the ventral area where they are feebly collared backward. The internal mold bears almost inconspicuous, fine, sinuous, prorsiradiate ribs on the less ornamented specimens (unnumbered, M135) to coarse, low, prorsiradiate, biconcave ribs, arising at the umbilical seam and tending to branch at mid flanks on strongly ornamented specimens (CASG70781-85). When the shell is preserved, the constrictions are replaced by slightly biconcave, strong, prorsiradiate ribs that cross the venter without diminution, where they are slightly projected forward. The intercalatories arise at the umbilical seam or at the inner third of the flanks and are mostly attenuated on the siphonal area. With age, the costation becomes coarser and feebler on both internal mold and shell. The largest available specimen (CASG70778: Figs 5, 6), has an estimated diameter of 180 mm, comprising a 80° sector of body chamber, which is crushed and weathered, seeming to retain only inconspicuous ribbing and feeble growth striae on the shell. The suture (Fig. 4c) is moderately divided, having a deep L and a strongly retracted suspensive lobe, and it is very close to the partial suture figured by Jacob (1906, text fig. 3) (fig. 2d).

Discussion. The measurements given by Dutour (2005) for the material from south-east France, and those of the Californian material are consistent. The Californian ammonites differ from the lectotype of Zuercherella zuercheri (Jacob, 1906, pl. 2, fig. 1), by their narrowly convex venter, wider constrictions that are slightly projected forward on the venter, stronger, broader, coarser ribs and a slightly wider umbilicus. Zuercherella latecostata (Riedel, 1938) from the Upper Aptian of Colombia, differs from our material by the presence of numerous strong collared ribs that tend to bifurcate on the outer part of the flanks and its lower whorl section. Zuercherella etayosernay Bogdanova and Hoedemaeker, 2004, from the Aptian–?Albian of Colombia, is characterized by its narrow umbilicus and feeble ornament.

The specimen figured as Zuercherella cf. zuercheri (Jacob, 1906) by Bogdanova and Hoedemaeker (2004, p. 245, pl. 41, fig. 2) is very close to the syntype figured by Jacob (1906, pl. 2, fig.1), herein refigured (fig. 2c).

Demay and Thomel (1986) proposed to assign specimens figured by Fallot as Uhligella zurcheri (1920, p. 261, pl. 3, fig. 7) to Zuercherella alpina (Demay and Thomel, 1986). These authors recognize three distinct species in the upper Aptian of the south-east of France, Zuercherella alpina occurring in lower part of the interval (Dufrenoyia furcata zone and base of the Epicheloniceras subnodosocostatum Zone), Zuercherella impressa and Z. zuercheri occurring in the upper part of the interval (Epicheloniceras subnodosocostatum Zone and Parahoplites melchioris Zone). The morphological differences between those three species concern the strength of the ornamentation on the juvenile growth stages but this material was neither described nor figured.

According to Dutour (2005, p. 144), it might be conceivable that the morphologies of the Dufrenoyia furcata Zone and those of the Parahoplites melchioris Zone belong to distinct species, but such an approach has still to be supported by further studies.

Occurrence. According to Dutour (2005), the species occurs with certainty from the Dufrenoyia furcata Zone to the upper part of the Parahoplites melchioris Zone (first half of Upper Aptian). The species has been reported from France, Switzerland (Jacob, 1906; Dutour, 2005), Germany (Kemper, 1964), Italy (Wiedmann and Dieni, 1968), Morocco (Rey et al., 1988), Georgia (Kvantaliani, 2005) and Venezuela (Renz, 1982). It occurs also in the Eotetragonites wintunius Zone and the base of the Acanthohoplites gardneri Zone, Upper Aptian of Shasta Co, California.

1. Conclusion

Zuercherella zurcheri is well-documented for a long time from North Tethyan margins and Germany (see the synonymy above). It has been sporadically reported from the south margin of Atlantic regions, in Morocco (Rey et al., 1988) but without any illustration, in Venezuela (Renz, 1982), and its presence is suspected in Colombia (Bogdanova and Hoedemaeker, 2004, see above) (Fig. 7). The species is reported for the first time in north California, and it is the first known record of a Tethyan ammonite species in the upper Aptian of northern California. Affinities between Tethyan and Northeast Pacific biota have been already suggested by Iba and Tanabe (2007), and Iba et al. (2011) during Upper Aptian time, based on the record of bivalvs. It is reasonable to assume that a migration path existed along the south Atlantic margin through the Colombian sea.

Further investigations among the abundant material housed in the California Academy of Sciences, San Francisco, would be required to better understand the affinities between Northeast Pacific, south Atlantic margin and Colombian biota.

Acknowledgments

We thank Peter Roopnarine, the late Jean DeMouthe, Christine Garcia, and Maricella Abarca (Academy of Sciences, San Francisco) for their assistance during our visits at the Academy. J.-L. Latil thanks Don McKenzie (Australia) for the fruitful discussions on the australian material, Fabienne Giraud (University of Grenoble, France) for her warm welcome in the paleontological collections, and a grant to Peter Sadler, University of California, Riverside, for bearing the costs of his numerous visits in California. Two anonymous reviewers are thanked for their helpful reviews, as well as Sandra Ramos and Josep Anton Moreno Bedmar for the editing work.

References

Amédro, F. and Robaszynski, F. (2005). Corrélation des successions de l’Albien par les ammonites entre la Province Nord-Pacifique et les Provinces européenne et arctique du Domaine boréal: zonation, eustatisme et paléobiogéographie. Geobios, 38, 585–607. DOI: https://doi.org/10.1016/j.geobios.2004.04.004

Anderson, F.M. (1902). Cretaceous deposits of the Pacific Coast. Proceedings of the California Academy of Sciences, Geology, 3(2), 154 p.

Anderson, F.M. (1938). Lower Cretaceous deposits in California and Oregon. Geological Society of America, special paper, 16, 339 p.

Bogdanova, T.N. and Hoedemaeker., P.J. (2004). Dehayesitidae, Oppeliidae, Desmoceratidae and Silesitidae of Colombia. In Donovan S.K. (Ed.), Early Cretaceous ammonites from Colombia. Scripta Geologica, 128, 183–312.

Breistroffer, M. (1947). Sur les zones d’Ammonites dans l’Albien de France et d’Angleterre. Travaux du Laboratoire de Géologie de Grenoble, 26, 88 p.

Casey, R. (1954). New genera and subgenera of Lower Cretaceous ammonites. Journal of the Washington Academy of Sciences, 44(4), 106–115.

Casey, R. (1961). A monograph of the Ammonoidea of the Lower Greensand, Pt. 3. Palaeontographical Society, 119–216.

Day, R.W. (1968). Biostratigraphy and taxonomy of lower Cretaceous molluscan faunas from the Queensland portion of the Great Artesian Basin. Volume 2: taxonomic studies [Unpublished thesis]. The Australian National University, 585 p.

Demay, L. and Thomel, G. (1986). Tentative d’élaboration d’une chronologie hémérale de l’Aptien moyen (Système Crétacé). Comptes Rendus de l’Académie des Sciences, 2, 302/1, 29–34.

Dutour, Y. (2005). Biostratigraphie, évolution et renouvellements des ammonites de l’Aptien supérieur (Gargasien) du bassin vocontien (Sud-Est de la France) [Unpublished thesis]. Thèse Université Claude-Bernard – Lyon 1, 302 p.

Egoian, V. L. (1969). Ammonites from the Clansayésien beds of Western Caucasus // Geology and oil-and-gas content of the Western Peri-Caucasus and Western Caucasus. Transactions of Krasnodar Branch of the All-Soviet Scientific Oil Institute, 19, 126–188.

Etayo Serna, F. (1979). Zonation of the Cretaceous of Central Colombia by ammonites. Publicaciones Geológicas Especiales del Ingeominas, 2, 1–188.

Etheridge, R. (1872). Description of the Palaeozoic and Mesozoic Fossils of Queensland. Quarterly Journal of the Geological Society, 28, 317–50.

Fallot, M. P. (1920). Observations sur diverses espèces de la faune du Gargasien bathyal alpin et en particulier sur la faune de Blieux. In Contribution à l´étude des céphalopodes paléocrétacés du sud-est de la France. Éditions Ministère des Travaux Publics, Imprimerie Nationale, 229–272.

Fülöp, J. (1964). A Bakonyhegység alsó-kréta (Berriázi-Apti) képzódményei (Lower Cretaceous deposits (Berriasian-Aptian) of the Bakony Mountains). Geologica Hungarica, Series Geologica, 13, 194 p.

Gray, A. R. G., McKillop, M. and McKellar., J. L. (2002). Eromanga Basin Stratigraphy. In Draper, J.J. (Ed.), Geology of the Cooper and Eromanga Basins, Queensland, (pp. 30–56). Queensland Minerals and Energy Review Series, Queensland Department of Natural Resources and Mines.

Hyatt, A. (1889). Genesis of the Arietidae. Smithsonian Contributions to Knowledge n° 673. Washington D.C., xi + 238 p.

Iba, Y., Sano, S.I. and Tanabe, K. (2011). A Tethyan bivalve, Neithea (Cretaceous pectinid) from northern California, and its biogeographic implications. Paleontological Research, 15(2), 62–67. DOI: https://doi.org/10.2517/1342-8144-15.2.062

Iba, Y., and Tanabe, K. (2007). Albian ammonite biogeography in the North Pacific. In Abstract Volume of the 7th International symposium Cephalopoda – Present and Past, 98–99.

Imlay, R. W. (1961). Characteristic Lower Cretaceous megafossils from Northern Alaska. Geological Survey Professional Paper, 335, 1–66.

Jacob, C. (1906). Etude stratigraphique et paléontologique du Gault de la vallée de la Engelberger AA (Alpes calcaires suisses, environs du lac des quatres cantons). In Jacob, C., and A. Tobler, Mémoires de la Société Paléontologique Suisse, 33, 3–26.

Jacob, C. (1907). Études paléontologique et stratigraphique sur la partie moyenne des terrains crétacés dans les Alpes françaises et les régions voisines [Thèse]. Faculté des Sciences de Paris, 315 p.

Jacob, C. (1908). Etude sur quelques ammonites du Crétacé moyen. Mémoires de la Société Géologique de France, Paléontologie, 28, 63 p.

Joly, B. and Delamette, M. (2008). Les Phylloceratoidea (Ammonoidea) aptiens et albiens du bassin vocontien (Sud-Est de la France). Carnets de Géologie/Notebooks on Geology, Mémoire 2008/04 (CG2008_M04), 1–60. Doi: https://doi.org/10.4267/2042/19113

Kemper, E. (1964). Einige Cephalopoden aus dem Apt des westlichen Norddeutschland. Fortschritte in der Geologie von Rheinland und Westfalen, 7, 31–66.

Kemper, E. (1971a). Geologischer Führer durch die Grafschaft Bentheim und die angrenzenden Gebiete [book]. Heimatverein der Grafschaft Bentheim Nordhorn, 4. Auflage, 172 p.

Kemper, E. (1971b). Zur Gliederung und Abgrenzung des norddeutschen Aptium mit Ammoniten. Geologisches Jahrbuch, 89, 359–390.

Kemper, E. (1976). Geologischer Führer durch die Grafschaft Bentheim und die angrenzenden Gebiete mit einem Abriss der emsländischen Unterkreide [book]. Heimatverein der Grafschaft Bentheim Nordhorn, 5. Auflage. 206 p.

Kemper, E. (1995). Die Entfaltung der Ammoniten und die Meeresverbindungen im borealen Unter- und Mittel-Apt. Geologisches Jahrbuch Reihe, A 141, 171–199.

Kennedy, W.J. (2000). Integrated stratigraphy across the Aptian-Albian boundary in the Marnes bleues, at Col de Pré-Guittard, Arnayon (Drôme), and at Tartonne (Alpes-de-Haute-Provence), France: a candidate Global Boundary Stratotype Section and Boundary Point for the base of the Albian Stage. In Kennedy, W. J., Gale, A. S., Bown, P. R., Caron, M., Davey, R. J., Gröcke, D., and Wray, D. S., Cretaceous Research, 2, 591–720.

Kilian, W. (1910). Erste Abteilung: Unterkreide (Palaeocretacicum). Lieferung 2: Das bathyale Palaeocretacicum im südostlichen Frankreich; Valendis-Stufe; Hauterive-Stufe; Barreme-Stufe; Apt-Stufe. In: Frech, F. (Ed.) Lethaea Geognostica. II. Das Mesozoicum, Band 3 (Kreide) (1907-1913). Schweizerbart. Stuttgart, 169–288.

Klein, J. and Vašiček, Z. (2011). Lower cretaceous ammonites. V, Desmoceratoidea Fossilium catalogus. I, Animalia, Pars 148, 311 p. Leiden: Blackhius.

Kvantaliani, I. V. (1971). The Aptian Ammonites of Abkhazia. Gruzinskii Polytechnitcheskii Institut im V.I. Lenina, Tbilissi, 175 p. (in russian)

Kvantaliani, I. V. (2005). In Kotetishvili, E. V., Kvantaliani, I. V., Kakabadze, M. V., and Tsirekidze, L. R. (Eds.), Atlas of early Cretaceous Fauna of Georgia, 788 p. (in Russian)

Latil, J. -L., Murphy, M. A. and Rodda, P. U. (2023). A review of Beudanticeras Hitzel, 1902 and its occurrence in the Cottonwood District of Northern California (Cretaceous, Ammonoidea). This volume.

Luppov, N. P., Bodylevsky, V. I. and Glazunova, A. E. (1949). Class cephalopoda). In Luppov, N.P. (Ed.), Atlas of index forms of the fossil faunas of the USSR, vol. 10. Gostgeolizdat. Moskva & Leningrad, 328 p. (in Russian)

Luppov, N. P., and Drushchits, V. V. (1958). Fundamentals of Paleontology. A manual for paleontologists and geologists of the USSR. Vol. VI. Mollusca - Cephalopoda II. Ammonoidea (Ceratita and Ammonitida), Endocochlia, Coniconchia [Book]. Gosudarstvennre Nauchno-Tekhnicheskoe Izdatel’stvo Literatury po Geologii i. Okhrane Nedr, 370 p.

Murphy, M. A. (1956). Lower Cretaceous stratigraphic units of northern California. The Bulletin of the American Association of Petroleum Geologists, 40(9), 2098–2119.

Murphy, M. A. (1967a). The ammonoid subfamily Gabbioceratinae Breistroffer. Journal of Paleontology, 41(3), 595–607.

Murphy, M. A. (1967b). Aptian and Albian Tetragonitidae (Ammonoidea) from northern California. University of California Publications in Geological Sciences, 70, 32 p.

Murphy, M. A. and Rodda, P. U. (2006). California Early Cretaceous Phylloceratidae (Ammonoidea). University of California Riverside, Campus Museum Contribution, 7, 98 p.

Mutterlose, J. (1996). Die Litho- und Biostratigraphie des Apt der Tongruben Schnermann am Rothenberge. Geologie und Paläontologie in Westfalen, 45, 41–58.

Orbigny, d’A., 1841, Paléontologie Française. Tome premier. Terrains crétacés. Céphalopodes: Masson, Paris, Librairie Victor, 662 pp.

Pervinquière, L. (1907). Étude de paléontologie tunisienne. 1 : Céphalopodes des terrains secondaires. Mémoires de la carte géologique de Tunisie, 438 p.

Rawlings, D. J., Haines, P. W., Madigan, T. L. A., Pietsch, B. A., Sweet, I. P., Plumb, K. A. and Krassay, A. A. (1997). Arnhem Bay-Gove, Northern Territory [Map]. 1:250 000 geological map series, Explanatory Notes. Sheets SD53-3,4., Northern Territory Geological Survey, 1v, 113p.

Renz, O. (1982). The Cretaceous ammonites of Venezuela [Book]. Birkhaüser Verlag Eds, 132 p.

Rey, J., Canerot, J., Peybernes, B., Tal-Eddine, K. and Thieuloy, J. P. (1988). Lithostratigraphy, biostratigraphy and sedimentary dynamics of the Lower Cretaceous deposits on the northern side of the western High Atlas (Morocco). Cretaceous Research, 9(2), 141–158. DOi: https://doi.org/10.1016/0195-6671(88)90014-6

Riccardi, A. C. and Medina, F. A. (2002). The Beudanticeratinae and Cleoniceratinae (Ammonitida) from the Lower Albian of Patagonia. Revue de Paléobiologie, 21(1), 291–351. URI : http://sedici.unlp.edu.ar/handle/10915/153053

Riedel, L. (1938). Amonitas del Cretácico inferior de la Cordillera Oriental. Estudios geológicos y paleontólogicos sobre la Cordillera Oriental de Colombia, 2. Departamento Minas y Petróleos, Ministerio de Industria y Trabajo de la Republica Colombia, 7–80.

Rodda, P. U. and Murphy, M. A. (2022). Cretaceous Desmoceratine ammonites (Mollusca, Cephalopoda) of the Cottonwood district, northern California. University of California Riverside, Campus Museum Contribution, 9, 44 p.

Rouchadzé, I. (1933). Les ammonites aptiennes de la Géorgie occidentale. Bulletin de l’Institut géologique de Géorgie, 1/3 (1932), 165–273.

Rozefelds, A. C., McKenzie, E. D. and Mobbs, D. C. (1990). Type, figured and mentioned fossil invertebrates in the Queensland Museum. Memoirs of the Queensland Museum, 28(2), 665–713.

Schindewolf, O. H. (1966). Studien zur Stammesgeschichte der Ammoniten. V. Abhandlungen Akademie der Wissenschaften und der Literatur Mainz, Mathematisch-Naturwissenschaftlichen Klasse, No. 1966, 3, 329–454.

Scotese, C. R. (2014). Atlas of Early Cretaceous Paleogeographic Maps, PALEOMAP Atlas for ArcGIS, volume 2, The Cretaceous, Maps 23-31 [Map]. Mollweide Projection, PALEOMAP Project, Evanston, IL.

Sharikadze, M. Z. (1993). Functional significance of ammonoid septa and lobe lines. In: Phylogenetic aspects of paleontology. Proceedings of the XXXV VPO session, Nauka, 131–139. (in Russian)

Spath, L. F. (1923). A monograph of the Ammonoidea of the Gault. Palaeontographical Society (Monographs), 1–72.

Stanton, T. W. (1895). Contributions to the Cretaceous Paleontology of the Pacific coast. The Fauna of the Knoxville beds. Bulletin of the U.S. Geological Survey, 133, 132 p.

Szives, O. (2007). Aptian-Campanian ammonites of Hungary. Geologica Hungarica, series Palaeontologica, 57, 187 p.

Thomel, G. (1980). Ammonites [Book]. Serre. Nice, 227p.

Vine, R. R., Day, R. W., Milligan, E. N., Casey, D. J., Galloway, M. C. and Exon, N. F. (1967). Revision of the nomenclature of the Rolling Downs Group in the Eromanga and Surat Basins. Queensland Government Mining Journal, 67(786), 144–151.

Weber, M. (1996). Die Tongrube 4 der Ziegelei Schnermann in Rothenberge: Lithound Biostratigraphie eines Ober-Aptprofils in NW-Deutschland. Geologie und Paläontologie in Westfalen, 45, 75–103.

Whitehouse, F. W. (1928). Additions to the Cretaceous Ammonoidea of eastern Australia. Part 2 (Democeratidae). Memoirs of the Queensland Museum, 9, 200–206.

Wiedmann, J. and Dieni, I. (1968). Die Kreide Sardiniens und ihre Cephalopoden. Palaeontographia Italica, 64, 171 p.

Wright, C. W. (1957). Treatrise on Invertebrate Paleontology. Part. L. Mollusca 4, Cephalopoda, Ammonoidea. In R.C. Moore (Ed.), Geological Society of America and University of Kansas Press, 490 p.

Wright, C.W. (1996). Treatise on Invertebrate Paleontology. Part. L. Mollusca 4 revised, Cephalopoda, Ammonoidea. In Wright, C. W., Calloman, J. H., and Howarth, M. K (Eds). Geological Society of America and University of Kansas Press, 362 p.

Zittel, K. A. von (1884). Cephalopoda: 329-522. In Zittel, K.A. Handbuch der Palaeontologie, Band 1, Abt. 2, Lief 3. Oldenbourg. Munich and Leipzig.

Zittel, K.A. von (1895). Grundzüge der Palaeontologie (Palaeozoologie) [Book]. R. Oldenbourg, München/Leipzig, vii + 972 p.Figure 7. Paleogeographic map at the Upper Aptian with the distribution of Zuercherella zuercheri (Jacob, 1906) (map after Scotese, 2014).