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Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

A NEW ASSEMBLAGE FROM THE LATE IN CENTRAL CALIFORNIA, PART I: , BONY FISH, , AND IMPLICATIONS FOR THE AGE OF THE PURISIMA FORMATION WEST OF THE SAN GREGORIO FAULT

Robert W. Boessenecker*

* Department of Earth Sciences, Montana State University, Bozeman, MT 59715 [email protected]

Robert W. Boessenecker. 2011. A New Marine Vertebrate Assemblage from the Late Neogene Purisima Formation in Central California, Part I: Fos- sil Sharks, Bony Fish, Birds, and Implications for the Age of the Purisma For- mation West of the San Gregorio Fault. – Palarch’s Journal of Vertebrate Pa- laeontology 8(4) (2011), 1-30. ISSN 1567-2158. 30 pages + 8 figures, 1 table.

Keywords: Purisima Formation, , , , aves, osteichthyes

ABSTRACT

The Miocene to Pliocene Purisima Formation crops out in multiple transform fault bounded structural blocks in central California. As a result of poor exposure, strike slip fault offset, and uncertain intraformational correlations, some exposures of the Purisima Formation are not well dated. The San Gregorio section of the Purisima Formation occurs in the Pigeon Point Block, west of the San Gregorio Fault, along the coast of southern Halfmoon Bay. Ages based on invertebrate and diatom biostratigraphy support a to Early Pliocene age, while ash correlations indicate a much younger Middle to Late Pliocene (3.3-2.5 Ma) age. Ab- undant remains of marine vertebrates occur in the Purisima Formation. Recent fieldwork in the San Gregorio section identified a modest assemblage of 26 taxa, including sharks ( , Carcharodon sp., Cetorhinus maximus, cf. , oxy- rinchus, Pristiophorus sp., Squatina sp., and Sphyrna sp.), skates (Raja sp., cf. R. binoculata), bony fish Paralichthys( sp., Thunnus sp.), birds (Mancalla diegensis, Morus sp.), and 13 ma- rine taxa, including several new records for the Purisima Formation. The non- mammalian vertebrates of this assemblage are described herein. The vertebrate assemblage is utilized to evaluate previous biostratigraphic and tephrochronologic age determinations for the San Gregorio section. The stratigraphic range of Carcharodon carcharias, Raja sp., cf. R. binoculata, Mancalla diegensis, and some of the marine strongly indicate a Middle to Late Pliocene age for the upper and middle parts of the section, while a Late Miocene or Early Pliocene age is probable for the base of the section.

© PalArch Foundation 1 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

Introduction Chondrichthyes Hexanchidae In 1827, the surveyor of the HMS Blossom, cf. Hexanchus Lt. Edward Belcher, reported “petrified Pristiophoridae of a cylindrical form” from coastal cliffs near Pristiophorus sp. modern day Santa Cruz, California (Vander- Squatinidae hoof, 1951: 109-110). These were probably ceta- Squatina sp. cean vertebrae from exposures of the Purisima Cetorhinidae Formation and constitute one of the earliest Cetorhinus maximus records of fossil vertebrates collected from the west coast of (Powell, 1998). Carcharodon carcharias Several decades later, a partial odontocete ros- Carcharodon sp. trum was designated as the holotype of Loncho- Isurus oxyrinchus delphis occiduus by the preeminent anatomist Sphyrnidae Joseph Leidy (1868). The specimen was collect- cf. Sphyrna ed from Miocene rocks near ‘Halfmoon Lake’ (a Rajidae probable corruption of Halfmoon Bay), suggest- Raja sp., cf. R. binoculata ing this fossil likely originated from the Puri- Osteichthyes sima Formation (Barnes, 1976; Powell, 1998). Scombridae Aside from a few isolated cetacean and pinni- Thunnus sp. ped bones mentioned by Repenning and Ted- Paralichthyidae ford (1977) and Barnes (1976), few other ma- Paralichthys sp. rine vertebrate have been reported from Aves the extensive exposures around Halfmoon Bay. Sulidae Much richer vertebrate assemblages have been Morus sp. collected from the Purisima Formation at Point Alcidae Reyes and Santa Cruz (see Palaeontologic Back- Mancalla diegensis ground). Mammalia In August 2004 the author and T. Palladino Pinnipedia investigated exposures of the Purisima Forma- Otariidae tion near Halfmoon Bay, based on reports of Otariidae indet. whale bones by local surfers. Multiple prolific Odobenidae bonebeds were discovered during fieldwork in Dusignathus sp. 2005 and 2006. A diverse vertebrate assemblage Odontoceti comprising 26 taxa (table 1) of sharks (Carchar- Odontoceti indet. odon carcharias, Cetorhinus maximus, cf. Hexan- Delphinidae chus, Isurus oxyrhincus, Pristiophorus sp., Squa- Globicephalinae indet. tina sp., and cf. Sphyrna), skates (Raja sp., cf. R. binoculata), bony fish (Paralichthys sp., Thun- sp, cf. P. sternbergi nus sp.), birds (Mancalla diegensis, Morus sp.), Phocoenidae (Dusignathus sp., Otariidae indet.), New and and cetaceans (Parapontoporia sp., Phocoenidae Phocoeninae indet. new genus, Phocoeninae indet., Globicephali- Mysticeti nae indet., Odontoceti indet., sp. in- Balaenidae det.1, Balaenidae sp. indet. 2, Balaenopteridae Balaenidae sp. indet. 1 indet., Balaenopteridae, new species, Herpetoce- Balaenidae sp. indet. 2 tus bramblei, Herpetocetus sp.) was established. Balaenopteridae These include several new vertebrate records Balaenopteridae indet. for the Purisima Formation, and potentially Balaenopteridae, new species new cetacean taxa (Boessenecker, 2006). These sensu stricto Herpetocetus bramblei c Table 1. List of fossil vertebrate taxa preserved in the Herpetocetus sp. San Gregorio section of the Purisima Formation, Halfmoon Bay, California.

© PalArch Foundation 2 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) localities are within the San Gregorio section of Institutional Abbreviations the Purisima Formation (Powell et al., 2007), an informal name applied to Purisima Formation SCMNH, Santa Cruz Museum of Natural His- strata on the west side of the San Gregorio Fault tory, Santa Cruz, California, USA; (and therefore in the Pigeon Point Structural SDNHM, Natural History Museum, Block), in the southern part of Halfmoon Bay, San Diego, California, USA; San Mateo County, California (figure 1). This UCMP, University of California Museum of Pa- section was initially mapped as the Late Mio- leontology, Berkeley, California, USA. cene Tahana Member (Cummings et al., 1962) on lithologic grounds. However, conflicting Palaeontologic Background age data exist for this section, including a Late Miocene age based on previous biostratigraphy Despite the abundance of vertebrate fossils in (Durham & Morgan, 1978; Gavigan, 1984), and the San Gregorio section of the Purisima Forma- a Middle Pliocene age supported by tephrochro- tion, only three previous studies have addressed nologic correlations and recent molluscan bio- them. In 1907 D. S. Jordan reported a single tooth (Sarna-Wocjicki et al., 1991; Powell of the Carcharodon “arnoldi” (identified as et al., 2007). The aim of this paper is to describe Carcharodon carcharias in this report) from the the non-mammalian marine vertebrates, and ‘Pliocene of Pescadero.’ A fragmentary, putative discuss the age of the San Gregorio section of physeteroid rostrum collected by R.M. Touring the Purisima Formation in light of this new ma- was mentioned by Packard (1962). In their de- rine vertebrate assemblage. scription of the Purisima Formation in the Half- moon Bay region, Cummings et al. (1962) noted the presence of cetacean bones at the base of Materials and Methods the San Gregorio section. Additional studies re- The fossils described herein were collected in garding other Purisima Formation vertebrates 2005 and 2006 from coastal exposures, speci- include mention, discussions, or descriptions of mens were recovered from the cliff face as well sharks (Stewart & Perry, 2002), pinnipeds (Kel- as screen washing of sediment. Specimens were logg, 1927; Mitchell, 1962; Repenning & Ted- prepared at Montana State University Depart- ford, 1977; Barnes & Perry, 1989; Boessenecker & ment of Earth Sciences and the Museum of the Perry, 2011), sirenians (Domning, 1978), and ce- Rockies in Bozeman, MT. Terminology for chon- taceans (Leidy, 1868; Glen, 1959; Packard, 1962; drichthyan teeth follows Purdy et al. (2001). Barnes, 1976, 1985; Pyenson & Brudvik, 2007; Terminology for batoid cranial morphology fol- Boessenecker & Geisler, 2008; Whitmore & lows Dean & Motta (2004). Terminology for avi- Barnes, 2008; Boessenecker et al., 2009; Good- an osteology follows Howard (1929). Detailed win et al., 2009). With the exception of fossil locality data are available to qualified research- material described by Kellogg (1927), Mitchell ers upon request. (1962), Repenning & Tedford (1977), Barnes Although the Pliocene- boundary (1985) and Whitmore & Barnes (2008), very few has recently been changed from 1.806 Ma to vertebrate fossils from the Purisima Formation 2.588 Ma due to inclusion of the Stage have been described in sufficient detail. within the Pleistocene and modification of the (Gibbard et al., 2009), this change is Geologic Background based on chronostratigraphy and does not re- flect the biostratigraphic integrity of the tradi- The upper Neogene Purisima Formation in cen- tionally defined Pleistocene epoch (Aubryet al., tral California is a grouping of Miocene and Plio- 2009). Thus, for the purposes of this paper, the cene marine sandstones, siltstones and mud- traditional definition as delineated in Gradstein stones representing deposition in shoreface to et al. (2004) of the Pliocene-Pleistocene bound- outer shelf and continental slope settings (Nor- ary at the 1.806 Ma Gelasian-Calabrian stage ris, 1986). The Purisima Formation occurs in boundary is retained along with a threefold four distinct structural blocks (and subblocks) division of the Pliocene epoch (Lower, Middle west of the San Andreas Fault (figure 1), and and Upper, equivalent with the , Pia- scattered exposures exist with significant fault cenzian, and Gelasian stages, respectively). displacement (Powell et al., 2007). Exposures of

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Figure 1. Generalized geologic map of part of central California, showing relevant tectonic features, and major localities and exposures of the Purisima Formation. Inset shows California and box showing location of map. L.H. subblock = La Honda subblock of the Santa Cruz structural block; Capitola subblock is also part of the Santa Cruz structural block. Faults are shown as black lines, or dashed where uncertain. the Purisima Formation vary in terms of their and 4) in the Santa Cruz Mountains (between stratigraphic succession, lithology, thickness, the San Andreas and Zayante faults in the La outcrop quality, fossil occurrence, fossil pres- Honda subblock of the Santa Cruz structural ervation and abundance, which have impeded block). The northernmost exposures at Point attempts at intraformational correlations. The Reyes (figure 1) in Marin County (65 km north Purisima Formation crops out in four primary of San Francisco) were originally named the areas in central California: 1) Point Reyes (Point Drakes Bay Formation (Galloway, 1977), but lat- Reyes Structural Block); 2) the Halfmoon Bay er recognized as including the Santa Margarita region (La Honda subblock of the Santa Cruz Sandstone, Santa Cruz Mudstone, and Purisima Structural Block, and Pigeon Point Structural Formation (Clark et al., 1984). The exposures of Block); 3) southern Santa Cruz County (Capito- the Purisima Formation in coastal Santa Cruz la subblock of the Santa Cruz Structural Block), County (approximately 100 km south of San

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Francisco; figure 1) range from 6.9 to about 2.5 Ma, are the best exposed, best studied, and most accurately dated Purisima Formation exposures. Additionally, they were recently designated as a supplementary reference section (Powell et al., 2007). Localities from the lower and middle portions of this section have yielded diverse ver- tebrate assemblages (see Palaeontologic Back- ground, above) that are currently under study (Perry & Boessenecker, unpublished data). In central San Mateo County (the La Honda subblock), the Purisima Formation is divided into five distinct members (Cummings et al., 1962). The type section of the Purisima Forma- tion is exposed south of Halfmoon Bay (figure 1) near Purisima Creek (Haehl & Arnold, 1904), which is now accessible only by boat. The strati- graphic relationships of the type section and the five members named by Cummings et al. (1962) remain unclear. These members are, from oldest to youngest, the Tahana Sandstone, Pomponio Mudstone, San Gregorio Sandstone, Lobitos Mudstone, and Tunitas Sandstone. The San Gregorio section (figure 1) has previously been mapped as the Tahana Member (Upper Miocene; Cummings et al., 1962), and these coastal cliffs were even designated as an al- ternative type section for the Tahana Member (Cummings et al., 1962). However, Powell et al. (2007) concluded that these strata should not be mapped as the Tahana Member, because ash correlations and and the occurrence of the mol- lusk Patinopecten healyi suggested a Pliocene age, younger than the Upper Miocene Tahana Member. The strata composing the San Gregorio sec- tion (figure 2) are gently folded into an easterly dipping syncline-anticline pair. Rocks from the Figure 2. Simplified stratigraphic column of the San entire section are light-brown to tan, fine to very Gregorio section, showing approximate stratigraphic fine-grained sandstones and coarse siltstone. positions of UCMP vertebrate localities, ash beds, and diatom assemblages. Because the thickness of missing The sandstones are massively bedded due to section is undetermined, the upper part of the San pervasive bioturbation that has homogenized Gregorio section is measured separately. the sediment. However, in certain horizons dis- tinct burrows (Ophiomorpha, Teichichnus pesca- cur in these shell beds. Vertebrate fossils are deroensis) have been preserved. The uppermost typically confined to bonebeds in the middle of San Gregorio section is punctuated by several the section, although isolated bones and partial, 1-100 cm thick white tephra beds. Body fossils disarticulated occur near the base of and molds of mollusks are restricted to the up- the section. Bonebeds in the middle of the sec- per third of the San Gregorio section, where tion contain a mix of unabraded complete and they sporadically occur as isolated bioclasts or fragmented bones, mollusk shells, and prismati- (more commonly) within laterally extensive, cally calcified batoid . Vertebrate skel- thin shell-rich beds. Rare phosphatized crusta- etal concentrations that exhibit more evidence cean remains, often in phosphate nodules, oc- of time-averaging and reworking contain rare,

© PalArch Foundation 5 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) abraded fragments, pebbles, molluscan tion. While the molluscan fossils reported thus steinkerns, crustacean fragments, and phos- far (Cummings et al., 1962; Durham & Morgan, phatic nodules, and lack calcareous mollusk el- 1978; Gavigan, 1984) were collected from the ements. Shark and mammal teeth are rare in upper part of the San Gregorio section, Powell these concentrations, as well as all other Purisi- et al. (2007) reported a diatom flora from the ma Formation deposits. Rare vertebrate fossils base of the San Gregorio section (figure 2) that occur within occasional shellbeds in the upper- was correlative with the Late Miocene Nitzchia most San Gregorio section. reinholdii zone (6.4-5.6 Ma). Naeser (in Gavigan, 1984) reported a 5.2 ±1.2 Age Ma fission track date from zircon grains within The age of the Purisima Formation varies from a rhyolitic tuff unit in the uppermost San Grego- one tectonic block to another and incidentally rio section. Sarna-Wocjicki et al. (1991) chemi- inter-block correlations have proven difficult cally correlated this upper tephra unit (figure 2) (Clark & Brabb, 1978; Powell, 1998; Powell et in the uppermost San Gregorio section with the al., 2007). The San Gregorio section was initially 2.5 Ma Ishi Tuff Member of the Tuscan Forma- mapped as the Tahana Member, and considered tion, in contrast to the numerous Late Miocene to be Late Miocene in age (supported by Dur- age determinations mentioned above. Recently ham & Morgan, 1978). Based on invertebrate Powell et al. (2007) reported additional tephra fossils, Cummings et al. (1962) suggested that correlations; the aforementioned upper unit was the Tahana Member was probably correlative again correlated with the 2.5 Ma Ishi Tuff, while with the Upper Miocene Jacalitos Formation another tephra unit in the middle of the San of central California, although it is not clear if Gregorio section (figure 2) was correlated with invertebrate fossils from localities west or east the 3.35 Ma Putah Tuff Member of the Tuscan (or both) of the San Gregorio fault were used and Tehama Formations. These dates (3.35-2.5 for this determination (since the Tahana Mem- Ma) led Powell et al. (2007) to conclude that the ber was mapped on both sides of the fault). Mi- San Gregorio section of the Purisima Formation crofossils from the Tahana Member in the La is Pliocene in age and should not be mapped Honda subblock (east of the San Andreas Fault) as the Tahana Member, as opposed to the Late indicate a latest Miocene age of 6.4-5.3 Ma, Miocene determinations of Durham & Morgan while the Pomponio, San Gregorio, Lobitos, and (1978) and Gavigan (1984). The discordance Tunitas Members are of younger, undetermined between age determinations derived from bio- Pliocene age (Powell et al., 2007). stratigraphy and tephrochronology can be fur- Based on mollusks and echinoids, Purisima ther investigated by utilizing the fossil verte- Formation strata were correlated with the up- brates (and their known stratigraphic ranges) per Jacalitos Formation by Durham & Morgan from this section as an independent test. (1978). The presence of three species of Lituy- apecten led Durham & Morgan (1978) to cor- Systematic Palaeontology relate the ‘Tahana Member’ in the San Gregorio section with Upper Miocene strata of the Falor Formation (now known to be latest Pliocene to Class Chondrichthyes Huxley, 1880 Pleistocene in age; Nilsen & Clarke, 1989) of Buen, 1926 northern California, and the Ohlson Ranch and Hexanchidae Gray, 1851 ‘Merced’ (= Wilson Grove Formation; Powell et Genus Hexanchus Rafinesque, 1810 al., 2004) Formations north of San Francisco. cf. Hexanchus These correlations indicated a Late Miocene to Early Pliocene age for the San Gregorio section Figures 3.1-3.2 (Durham & Morgan, 1978; Powell et al., 2007). Gavigan (1984) correlated the San Gregorio sec- Material examined – One tooth, UCMP tion with an Upper Miocene portion of the Wil- 219010, from UCMP Locality V99851. son Grove Formation north of San Francisco Discussion – This specimen is an upper an- due to the occurrence of Lituyapecten turneri. terior hexanchid tooth (figures 3.1-3.2). It bears Powell et al. (2007) reported the Pliocene bivalve an incomplete, but robust root with a distinct Patinopecten healyi from the San Gregorio sec- triangular mesial lobe. The root is robust lin-

© PalArch Foundation 6 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) gually, flat labially, and is nearly flush with the smooth cutting edges of the tooth makes the labial surface of the primary . The distally specimen referable to Pristiophorus, as it lacks inclined, elongate primary cusp is robust basal- the barbs typical of the genera Pliotrema and ly, and is labially recurved in mesial view. The Ikamauius (Keyes, 1979). The crown gradually cutting edge continues smoothly to its termina- tapers apically, has a straight posterior mar- tion at the root mesially and distally. No cus- gin, and a convex anterior margin. The crown plets are present on the mesial or distal heels of is about 10 mm long. Most of the root is not the primary cusp. preserved. The length of this specimen overlaps The primary cusp of this specimen differs fossil specimens of Pristiophorus lanceolatus from Heptranchias by being more robust and and extant specimens of P. nudipinnus and P. not as distally inclined and recurved (Kemp, cirratus. The rostral tooth morphology of these 1978). This specimen differs from Notorhynchus species is very similar (Keyes, 1982); therefore, in lacking a square-shaped mesial root lobe, and a specific identification is not possible. a cutting edge that continues smoothly to its Pristiophorus has previously been reported termination rather than in a cusplet or a small from several northeast Pacific Tertiary forma- shoulder (Kemp, 1978). Reported fossil occur- tions. Welton (1972) reported Pristiophorus rences of Hexanchus in California include the from several geologic units in Oregon, includ- Lodo Formation (Welton, 1974), the ing the Lower Keasey Formation, Lower Miocene Skooner Gulch Formation (Phil- the Lower-Middle Oligocene Pittsburg Bluff lips et al., 1976), the Lower Miocene Jewett Sand Formation, and the Upper Oligocene-Lower Member of the (Mitchell & Miocene Nye Mudstone. Pristiophorus fossil oc- Tedford, 1973), the Round currences in California include the Lower Mio- Mountain Silt (Mitchell, 1965), the Upper Mio- cene Skooner Gulch Formation (Phillips et al., cene Santa Margarita Sandstone (Perry, 1993), 1976), the Lower-Middle Miocene Jewett and and from the Mio-Pliocene Santa Cruz section Olcese Sand Members of the Temblor Forma- of the Purisima Formation (Perry, 1977). Oth- tion (Olson & Welton, 1986), and the Lower er Northeast Pacific records include the Lower Pliocene Lawrence Canyon Local Fauna of the Miocene Nye Mudstone and the Lower Miocene San Mateo Formation (Barnes et al., 1981). As Astoria Formation of coastal Oregon (Welton, the San Gregorio section is herein determined 1972), and the Upper Miocene Almejas Forma- to be Late Pliocene, this is the youngest record tion of (Stewart, 1997; Barnes, of a from the northeast Pacific Ocean. 2008). Fossils of Hexanchus are known from the This indicates that became extinct Early to the Holocene and occur world- in this region no earlier than the Late Pliocene. wide (Cappetta, 1987). Extant sixgill sharks in- Extant sawsharks do not currently inhabit the habit continental shelves, slopes, and the abys- northeastern Pacific (Compagno et al., 2005). sal plain along oceanic margins in temperate, Fossil Pristiophorus have been reported from cold temperate, and some tropical waters world- Upper through Pliocene strata in wide (Compagno et al., 2005). Sixgill sharks are North America, Europe, Africa, Asia, , large, typically deep water predators that feed Antarctica, and (Keyes, 1982; Cap- on fish and invertebrates (Compagno, 1984). petta, 1987; Long, 1992; Gottfried & Rabarison, 1997). Extant Pristiophorus species inhabit the Order Pristiophoriformes Berg, 1958 Indian Ocean, northwest Pacific Ocean, and Family Pristiophoridae Bleeker, 1859 the northern Carribbean Sea (Compagno et al., Genus Pristiophorus Müeller & Henle, 1837 2005). Sawsharks inhabit inner shelf through Pristiophorus sp. continental slope environments (>100-630 m depth), and are small (1-1.5 m long) epibenthic Figures 3.3-3.4 predators that consume invertebrates and small fish (Compagno, 1984). Material examined – One rostral tooth, UCMP 219026, from UCMP locality V99847. Discussion – The dorsoventrally flattened, narrow crown identifies this as a sawshark ros- tral tooth (figures 3.3-3.4). The characteristically

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Figure 3. Elasmobranch teeth from the San Gregorio section of the Purisima Formation. 1-2, UCMP 219010, tooth of cf. Hexanchus (Rafinesque, 1810), in lingual and medial aspect (respectively); 3-4, UCMP 219026, rostral tooth ofPristiophorus sp. (Müller & Henle, 1837), in dorsal and distal aspect (respectively); 5-6, UCMP 219029, tooth of Squatina sp. (Dumeril, 1806), in lateral and labial aspect (respectively); 7-8, UCMP 212861, tooth of Carcharodon carcharias (Linnaeus, 1758), in lingual and labial aspect (respectively); 9-10, UCMP 219055, tooth of Squatina sp., in apical, lateral, and labial aspect (respectively); 12-13, UCMP 212860, tooth of Carcharodon carcharias in lingual and labial aspect (respectively); 14-15, UCMP 219025, tooth of Carcharodon carcharias in lingual and labial aspect (respectively); 16-17, UCMP 212863, tooth of Carcharodon carcharias in lingual and labial aspect (respectively); 18-19, UCMP 219011, tooth of Carcharodon carcharias in lingual and labial aspect (respectively); 20-22, UCMP 219022, tooth of Carcharodon sp. in lingual, labial, and mesial aspect (respectively); 23-25, UCMP 219023, tooth of Isurus oxyrinchus, in lingual, labial and mesial view (respectively); 26-27, UCMP 219024, tooth of Isurus oxyrinchus in lingual and labial aspect (respectively). Scale bar = 5 mm for 1-6 and 9-11, and 10 mm for 7-8 and 12-26.

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Order Squatiniformes Buen, 1926 cene of Baja California Family Squatinidae Bonaparte, 1838 (Stewart, 1997; Barnes, 2008), the Lower Plio- Genus Squatina Dumeril, 1806 cene Lawrence Canyon local fauna of the San Squatina sp. Mateo Formation (Barnes et al. 1981), and the Upper Pleistocene Palos Verdes Sand (Long, Figures 3.5-3.6, 3.9-3.11 1993b). Additional records from Baja Cali- fornia include the Middle Miocene Rosarito Material examined – Two teeth (UCMP Beach Formation (Deméré et al., 1984). Squa- 219029 and 219055) from UCMP localities tina is known from Jurassic through Pleisto- V99836 and V99837. cene strata worldwide (Cappetta, 1987; Long, Discussion – The narrow cusps with wide 1993b; Purdy et al., 2001). One extant species, heels, and wide-based, diamond shaped roots Squatina californica, currently inhabits waters oriented perpendicularly to the cusp identify off California (Ebert, 2003); other species of these teeth as the angel shark, Squatina (figures Squatina inhabit continental shelf and upper 3.5-3.6, 3.9-3.11). The narrow crown is 6.1 mm slope environments (0-400 m depth) world- long. Additional features of Squatina exhibited wide (Compagno et al., 2005). In general, angel in these specimens include enameloid ‘pegs’ sharks have dorso-ventrally compressed bodies protruding linguobasally from the base of the convergent with skates and rays, inhabit inner crown, narrow mesial and distal extensions of to outer shelf settings, and are small (1-2 m) the crown foot onto the sides of the root, and epibenthic ambush predators that prey on crus- lingual curvature of the crown. The equidimen- taceans, cephalopods, bony fish, and small elas- sional roots are much wider labiolingually than mobranchs (Compagno, 1984). the teeth of many species of Squatina, which often possess labiolingually compressed roots; Order Berg, 1958 this is exemplified by UCMP 219055. A slight Family Cetorhinidae Gill, 1862 bulge occurs on the lingual portion of the root. Genus Cetorhinus Gunnerus, 1765 The crown feet are oriented more steeply api- Cetorhinus maximus Gunnerus, 1765 cally (figures 3.6, 3.11), differing from extant Squatina dumeril, Squatina tergocellata, and Figures 5.1-5.6, 5.9-5.14 similar to Squatina californica, Squatina japon- ica, Squatina nebulosa, and Squatina australis. Material examined – Three teeth (UCMP In terms of the root narrowness (figure 3.6), 219015, 219020, and 219021), and gill raker this tooth compares best with S. californica and fragments (UCMP 219016-219018, 219050, S. japonica. Teeth of fossil species of Squatina 219073, 219074) from UCMP localities V99833, are very similar, and isolated teeth can be dif- V99840, V99845, V99849, V99854. ficult to confidently identify (Cappetta, 1987); Discussion – The referred teeth are small, given the similarity to several extant taxa and with tetrahedral roots lacking a nutrient groove small sample, this specimen is identified only (figures 5.5-5.6, 5.9-5.14). The crowns are tear- to the genus level. Teeth of Squatina sp. are also drop-shaped, lack crown feet, are not lingually- present elsewhere in the Purisima Formation, curved, and are basally narrower than the oral in the Middle portion of the Santa Cruz section teeth of the genera Rhincodon, and (UCMP and SCMNH collections). Squatina. The largest specimen (UCMP 219015) The genus Squatina has previously been re- has a 6.9 mm long crown, while the smallest ported from several other localities in Califor- specimen (UCMP 219020) has a 4.3 mm long nia, including the Paleocene Lodo Formation crown. These teeth bear a single, weakly devel- (Welton, 1974), the Lower Miocene Jewett and oped lateral cusplet (e.g. figure 5.6). These teeth Olcese Sand Members of the Temblor Forma- differ from the extinct species Cetorhinus par- tion (Mitchell & Tedford, 1973; Olson & Wel- vus by having teeth without distinct root lobes ton, 1986), the Lower Miocene Skooner Gulch and nutrient grooves; Miocene teeth referable Formation (Phillips et al., 1976), the Middle to Cetorhinus have traditionally been referred Miocene Round Mountain Silt (Mitchell, 1965), to C. parvus, and Pliocene teeth to C. maximus the Upper Miocene Santa Margarita Sandstone (Cappetta, 1987; Long, 1993a). Extant Cetorhi- (Domning, 1978; Perry, 1993), the Upper Mio- nus maximus display a wide variety of tooth

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Figure 4. Carcharodon teeth from the San Gregorio section of the Purisima Formation, and a comparison of serration size between Carcharodon carcharias and Carcharodon sp. 1-2, UCMP 212862, tooth of Carcharodon carcharias, in lingual and labial aspect (respectively); 3-4, UCMP 219013, tooth of Carcharodon carcharias in lingual and labial aspect (respectively); 5, cutting edge of fossil Carcharodon carcharias (UCMP 212863); 6, cutting edge of Carcharodon sp. (UCMP 219022); 7-8, UCMP 219014, tooth of Carcharodon carcharias in labial and lingual aspect (respectively); 9, UCMP 219064, tooth of Carcharodon carcharias in lingual aspect; 10, UCMP 219012, tooth of Carcharodon carcharias in lingual aspect. Scale bar = 10 mm for 1-4 and 7-10, and 5 mm for 5-6. morphologies (Shimada, 2002), and C. parvus similar to C. maximus, albeit smaller (Herman, teeth should be reanalyzed in light of recent ob- 1979; Long, 1993a). Cetorhinus fossils from servations of dental variation in C. maximus. California have been reported from the Lower The gill raker fragments from the San Gre- Miocene Jewett and Olcese Sands (Mitchell & gorio section are long (up to 21 mm; UCMP Tedford, 1973; Olson & Welton, 1986), the Mid- 219016) and less than one mm in width except dle Miocene Round Mountain Silt (Mitchell, at the anterior end, where the filament expands 1965), the Upper Miocene in width, curves, and connects to a hatchet- (Domning, 1978). Additional records from Baja shaped osteodentine root (figures 5.1-5.4). The California include the Middle Miocene Ysidro roots exhibit a minor anterior extension, and a Formation (Domning, 1978) and the Upper Mio- long posterior extension. The raker ‘crown’ is cene Almejas Formation (Stewart, 1997; Barnes, covered in smooth enameloid. These specimens 2008). Cetorhinus has an to Pliocene, are morphologically identical to those of extant worldwide fossil record (Cappetta, 1987; Cione & Cetorhinus maximus. Gill rakers of C. parvus are Reguero, 1998). The extant

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Figure 5. Elasmobranch teeth, gill rakers, and dermal denticles from the San Gregorio section of the Purisima Formation. 1, UCMP 219016, partial gill raker of Cetorhinus maximus (Gunnerus, 1765); 2, UCMP 219073, partial gill raker of Cetorhinus maximus; 3, UCMP 219074, partial gill raker of Cetorhinus maximus; 4, UCMP 219018, partial gill raker of Cetorhinus maximus; 5-6, UCMP 219015, tooth of Cetorhinus maximus, in lateral and labial aspect (respectively); 7-8, UCMP 219028, tooth of Sphyrna sp. (Rafinesque, 1810), in lingual and labial aspect (respectively); 9-11, UCMP 219021, tooth ofCetorhinus maximus, in lateral, labial, and lingual aspect (respectively); 12-14, UCMP 219020, tooth of Cetorhinus maximus, in lateral, labial, and lingual aspect (respectively); 15, UCMP 219044, dermal buckler of Raja sp., cf. R. binoculata (Girard, 1855), in external aspect; 16-17, UCMP 219041, dermal buckler of Raja sp., cf. R. binoculata, in lateral aspect; 18, UCMP 219072, dermal buckler of Raja sp., cf. R. binoculata, in external aspect; 19-20, UCMP 219047, dermal buckler of Raja sp., cf. R. binoculata, in lateral and external aspect (respectively); 21-22, UCMP 219063, dermal buckler of Raja sp., cf. R. binoculata, in lateral and external aspect (respectively). Scale bar = 10 mm for 1-4, and 15-22, and =5 mm for 5-14.

Cetorhinus maximus has an antitropical tem- feeder that feeds on planktonic invertebrates, perate distribution in the Pacific and Atlantic and inhabits continental shelf and slope waters Oceans, including California waters (Ebert, (Compagno, 1984; Compagno et al., 2005). 2003; Compagno et al., 2005). Cetorhinus maxi- mus is a gigantic (5-10 m long), epipelagic filter

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Family Lamnidae Müller & Henle, 1838 Recent studies have indicated that the ex- Genus Carcharodon Smith in Müller & Henle, tant evolved directly from 1838 hastalis through a number of Carcharodon carcharias Linnaeus, 1758 character changes, which includes the develop- ment of serrations (Muizon & DeVries, 1985; Figures 3.7-3.8, 3.12-3.22, 4.1-4.10 Nyberg et al., 2006; Ehret et al., 2009). Unser- rated Cosmopolitodus hastalis teeth occur in the Material examined – Eleven teeth (UCMP Oligocene and Miocene, and persist through the 212860-21863, 219011-219014, 219025, 219027, Late Miocene in the Pacific Basin, while teeth and 219064) from UCMP localities V99833, with small serrations identified asCarcharodon V99834, V99838, and V99857. sp. first occur in rocks of latest Miocene age Discussion – Jordan (1907) described and fig- (Yabe, 2000; Ehret et al., 2009). The serrations ured a tooth he referred to Carcharodon arnoldi of these teeth increase in size through time, from the San Gregorio section; Carcharodon ar- with Late Pliocene teeth having large serrations noldi and other species of Carcharodon named of identical size to extant Carcharodon carcha- from the Neogene of California were considered rias (Muizon & DeVries, 1985). This transition invalid by Cappetta (2006). The teeth reported has been observed in strata in , , and here are broad and triangular, and are labiolin- California (Muizon & DeVries, 1985; Yabe, gually compressed with irregular, coarse ser- 2000; Stewart & Perry, 2002; Ehret et al., 2009) rations on a cutting edge that continues to the and possibly Australia (Carcharodon sp. tooth, crown foot (figures 3.7-3.8, 3.12-3.22). In small- misidentified as Isurus escheri in Kemp, 1991: er teeth (UCMP 212862, 219013; figures 4.1-4.4, 151, Plate 19), suggesting that the Cosmopolito- 4.7-4.10) the serrations are very minute, and dus-Carcharodon transition was a Pacific Ocean- largest in larger teeth (UCMP 212863). Serra- wide phenomenon. tions are largest basally, and decrease in size to- The Cosmopolitodus-Carcharodon transition wards the apex of the tooth crown. These teeth has been observed in the Santa Cruz section of exhibit roughly 29-38 serrations on each cutting the Purisima Formation. Teeth of Cosmopolito- edge. Serrations of these specimens range from dus hastalis occur within the basal strata of the 10.5 to 16.6 serrations/cm; the largest serra- Purisima Formation near Santa Cruz; where tions occur on UCMP 212863 (figure 4.5). The glauconitic sand from the base of the Purisima root lobes are wide and flat and lack a -nutri Formation has yielded a K/Ar date of 6.9 ± 0.5 ent groove or torus (lingual protuberance) like Ma (Clark, 1966; Madrid et al., 1986). Carcharo- in extant Carcharodon carcharias. Root lobes of don sp. teeth with minute serrations occur in lower anterior teeth (UCMP 212861, 219014) a bed dated at 5.3 Ma (the ‘crab marker bed’ of are labiolingually robust; in UCMP 212861, the Madrid et al., 1986, which was identified as the root tips are tapered (figures 3.7-3.8). In up- Mio-Pliocene boundary by Powell et al., 2007). per anteriors (UCMP 212863, 219011) and up- Carcharodon sp. teeth with slightly larger ser- per laterals (UCMP 212860, 212862, 219013), rations occur in the ‘concretionary bed’ of the root lobes are labiolingually flattened and Perry (1989), which records a depositional hia- rectangular (figures 3.12-3.13, 3.16-3.17, 3.18- tus ranging from 4.5 to 3.47 Ma (Madrid et al, 3.19). These teeth differ from Carcharocles by 1986). These Carcharodon teeth have serrations lacking a chevron-shaped neck (sensu Cappetta, that are intermediate in size between Carcharo- 1987), lacking a lingually convex crown, lacking don sp. from the lower bed and extant Carchar- a torus, and having coarse, irregular serrations. odon carcharias (Stewart & Perry, 2002); this in- These teeth differ from Cosmopolitodus hastalis crease in serration size is similar to and appears by possessing serrations and from other species to be contemporaneous with the transition of Isurus by exhibiting wide, triangular crowns observed in the Pisco basin in Peru (Muizon & that are not distally inclined. The smallest tooth DeVries, 1985) and the Capistrano Formation in (UCMP 219064) has a crown height of 8.8 mm; (Stewart & Raschke, 1999). the largest specimen (UCMP 212863) is broken Fossils of Carcharodon have previously and has a crown width of 46 mm, and originally been reported from several other localities in probably measured approximately 50 mm in California, including the Pliocene Deguynos crown height. Formation (Mitchell, 1961), the Lower Pliocene

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Lawrence Canyon Local Fauna of the San Mateo men exhibits a much higher absolute number Formation (Domning, 1978; Barnes et al. 1981) per cutting edge, and the height of individual the Upper Miocene-Lower Pliocene Capistrano serrations is smaller than in comparably sized Formation (Stewart & Raschke, 1999), the Plio- teeth of Carcharodon carcharias (figures 4.5- Pleistocene (Deméré & 4.6). The serration size is similar to teeth of Car- Cerutti, 1982), and an unnamed Upper Pleisto- charodon sp. from the ‘crab marker bed’ of the cene unit near Newport Bay, California (Long, Santa Cruz section, and to teeth of Carcharodon 1993b; originally mapped to as the Palos Verdes sp. from the (Muizon & DeVr- Sand). Carcharodon has also been recorded in ies, 1985; Ehret et al., 2009). UCMP 219022 was the Mio-Pliocene Almejas Formation of Baja collected from the base of the San Gregorio California (Barnes, 1991, 2008; Stewart, 1997). section, which has yielded a diatom flora (fig- Other fossils of Carcharodon have been re- ure 2) correlative with the Late Miocene (6.4- ported from latest Miocene, Pliocene, and Pleis- 5.6 Ma) Nitzchia reinholdii zone (Powell et al., tocene fossil localities worldwide (Cappetta, 2007). The occurrence of teeth of Carcharodon 1987; Yabe, 2000; Purdy et al., 2001; Ehret et al., carcharias in the middle and upper parts of the 2009). The extant great white shark, Carchar- San Gregorio section with Pliocene mollusks odon carcharias, currently inhabits temperate and Late Pliocene ash correlations (3.5 and 2.5 waters worldwide, including coastal waters of Ma; Powell et al., 2007) suggests that part of the California (Ebert, 2003; Compagno et al., 2005). Cosmopolitodus-Carcharodon transition is rep- Carcharodon carcharias is a large (3-6 m long), resented by Carcharodon fossils within the San macrophagous predator that feeds on fish, elas- Gregorio section, in addition to the Santa Cruz mobranchs, sea turtles, birds, and small marine section. ‘Transitional’ teeth identified asCarcha - mammals, and frequents temperate epipelagic rodon sp. that possess minute serrations have and continental waters worldwide (Compagno, been reported from the Lower Pliocene of Japan 1984; Compagno et al., 2005). (Yabe, 2000), the Upper Miocene of Peru (Ehret et al., 2009), the Upper Miocene Capistrano For- Carcharodon sp. mation (Stewart & Raschke, 1999), and the ‘crab marker bed’ of the Santa Cruz section of the Figures 3.20-3.22, 4.6 Purisima Formation (Stewart & Perry, 2002).

Material examined – UCMP 219022, a tooth Genus Isurus Rafinesque, 1810 from UCMP locality V99851. Isurus oxyrinchus Rafinesque, 1810 Discussion – A specimen from the base of the San Gregorio section is a large lower sec- Figures 3.23-3.27 ond anterior tooth, and represents a different, earlier than Carcharodon carcharias. The Material examined – Two teeth (UCMP crown is broadly triangular and symmetrical 219023 and 219024) from UCMP locality (figures 3.20-3.22), with a flat labial surface with V99853. slight longitudinal enameloid wrinkles near the Discussion – Specimens include one upper root, and a lingual surface of the crown which lateral tooth (UCMP 219024), and a lower sec- is strongly convex. The root lobes are elongate, ond anterior tooth (UCMP 219023). The upper and the mesial root lobe is slightly longer than lateral tooth lacks lateral cusplets, has an un- the distal. A slight lingual protuberance is man- usually wide, gracile root, and a robust, wide, ifested on the strongly convex lingual portion smooth, and distally inclined crown (crown of the root (figure 3.22). The crown height of height of 30.2 mm) with a flat labial surface this tooth is 59 mm. This tooth differs from the and moderately convex lingual surface (figures teeth from higher in the section referred above 3.26-3.27). The smooth cutting edges of the to Carcharodon carcharias in the possession of crown are convex mesially, and nearly straight minute serrations. This tooth has 46 serrations distally. This tooth is superficially similar toIsu - on the distal cutting edge, and 11.5 serrations/ rus planus, due to the wide, relatively flat, dis- cm (figure 4.6). Although the number of serra- tally inclined crown. The lower anterior tooth tions per centimeter is similar to those reported (UCMP 219023) exhibits more typical morphol- above for Carcharodon carcharias, this speci- ogy for Isurus oxyrinchus, and has an elongate

© PalArch Foundation 13 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) crown (crown height of 25.6 mm) with a slight- (1997) from the Upper Miocene Almejas Forma- ly convex labial surface and a strongly convex tion of Baja California. Many other published lingual surface (figures 3.23-3.25). In distal as- records simply list “Isurus sp.” from Neogene pect, the crown is curved lingually for most of strata on the west coast of North America; many its length, and is labially curved at its apex (fig- of these in all likelihood represent additional re- ure 3.24). In labial aspect, the apex of the crown cords of this species. Isurus has a Paleocene to is mesially inclined, unlike Isurus paucus; this Pleistocene fossil record worldwide (Cappetta, tooth also exhibits a much labiolingually thick- 1987; Long, 1993b). The extant shortfin mako er crown than I. paucus, Isurus hastalis, and (I. oxyrinchus) inhabits temperate and tropi- I. planus, which typically have flattened crowns. cal waters worldwide, including the California While the upper lateral tooth (UCMP- coast (Ebert, 2003). Modern mako sharks are 219024) superficially resembles the Miocene large (2-4 m) epipelagic, macrophagous preda- taxon Isurus planus, it differs by having nar- tors that feed on cephalopods, fish, and small rower root lobes and a more convex lingual sur- marine mammals, and are the fastest swim- face of the crown. Additionally, I. planus is only ming sharks (Compagno, 1984; Compagno et confidently known from Oligocene through al., 2005). lowermost Upper Miocene strata around the Pacific rim. Records of I. planus in California Order Carchariniformes Compagno, 1973 include the Middle Miocene Round Mountain Family Sphyrnidae Gill, 1872 Silt (Mitchell, 1965), the Middle Miocene To- Genus Sphyrna Rafinesque, 1810 panga Canyon Formation (Howard & Barnes, cf. Sphyrna sp. 1987), the Middle to Upper Miocene Santa Mar- garita Sandstone (Domning, 1978; Perry, 1993), Figures 5.7-5.8 and the upper Miocene Monterey Formation (Domning, 1978). Further south, I. planus has Material examined – One tooth, UCMP also been reported from the Middle Miocene 219028, from UCMP locality V99836. Rosarito Beach Formation (Deméré et al., 1984), Discussion – This specimen is tentatively and the Plio-Pleistocene San Diego Formation referred to Sphyrna due its robust, distally in- in Baja California (Ashby & Minch, 1984). Ash- clined crown with convex margins, strong dis- by & Minch (1984) also recorded Carcharocles tal notch differentiating the cusp from the dis- from this locality, although neither tal crown foot, and minute serrations (figures C. megalodon nor I. planus have been found in 5.7-5.8), the combination of which identifies it the San Diego Formation since, and it is likely as a hammerhead shark (Cappetta, 1987). The that these specimens were actually collected crown height of this specimen is 6.3 mm; it also from the older Rosarito Beach Formation (the has a large root with a shallow nutrient groove I. planus specimen, SDNHM 29744, is now la- that does not reach the base of the crown. This beled as having been collected from this older specimen differs from Rhizoprionodon by hav- unit). Records from Oregon include the Lower ing a broader primary cusp. UCMP 219028 ex- Miocene Astoria Formation (Welton, 1972), hibits similarities with extant Sphyrna mokarran and the Upper Miocene (8.5-6.5 Ma; Prothero and Sphyrna zygaena, with its robust, distally et al., 2001) Empire Formation of Oregon (Ar- inclined primary cusp and minute serrations; nold & Hannibal, 1913). Other records indicate however, the incompleteness of this speci- I. planus was restricted to the Pacific Ocean, men precludes a specific identification. Fossil with reports from the Late Oligocene and teeth of are often misidentified Middle Miocene of Australia (Fitzgerald, 2004; as hammerhead shark teeth (Cappetta, 1987). Kemp, 1991), and the Middle and Late Miocene Welton (1972) reported a single occurrence of of Japan (Kuga, 1985; Nakano, 1999). Sphyrna in the Upper Eocene Spencer Forma- Californian records of Isurus oxyrinchus in- tion of Oregon. Sphyrna has previously been clude the Upper Miocene Santa Margarita Sand- reported in California and Baja California from stone in Santa Cruz County (Perry, 1993), and the Lower Miocene Jewett Sand (Mitchell & the Miocene/Pliocene San Mateo Member of Tedford, 1973), the Middle Miocene Rosarito the Capistrano Formation (Barnes et al., 1981). Beach Formation (Deméré et al., 1984), the Isurus oxyrhinchus was also reported by Stewart Middle Miocene Round Mountain Silt (Mitch-

© PalArch Foundation 14 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) ell, 1965) and the Mio-Pliocene Capistrano For- in areas of slight abrasion and in cross section. mation (Bonner & Gilmour, 1988). Additionally, The surface texture is primarily fibrous, con- Welton (1972) reported a single occurrence of cealing the underlying prismatic cartilage. The Sphyrna in the Late Eocene Spencer Formation mandibular (figures 6.9-6.14) bear a of Oregon. Three extant species of Sphyrna can dorsoventrally compressed mesial portion that be found in California waters, including Sphyr- is curved anteriorly toward the symphysis. This na lewini, Sphyrna tiburo, and Sphyrna zygaena portion has subparallel anterior and posterior (Ebert, 2003). Extant hammerhead sharks in- margins, and is wider toward the quadratoman- habit temperate and tropical continental shelves dibular joints. An elongate, shallow fossa is ori- and slopes (0-275 m depth) worldwide, and are ented diagonally in an anterolateral direction medium sized (1-6 m) epipelagic predators that across the lingual surface of the mandibular feed on invertebrates, bony fish, and other elas- cartilage (figure 6.13). Rough surface texture mobranchs (Compagno, 1984; Compagno et al., characterizes the fossa, often with parasagittal 2005). striations; this region corresponds to the dental file-bearing portion of the mandibular cartilage. Order Rajiformes Berg, 1940 On the posterolabial margin of the element lies Family Rajidae Blainville, 1816 the sustentaculum, which forms a parasagittal Raja Linnaeus, 1758 ridge, as well as a dorsolaterally oriented pro- Raja sp., cf. R. binoculata Girard, 1855 cess, the dorsal flange of the sustentaculum. In extant batoids, the dorsal flange articulates with Figures 5.15-5.22, 6.3-6.14 the hyomandibula, the sole cranial connection of the jaws (Dean & Motta, 2004). Immediately Material examined – Multiple palatoquad- posterior to this is the mandibular articular fos- rate (UCMP 219068-219070) and mandibular sa, which receives the palatoquadrate condyle. cartilages (UCMP 219033, 219034, 219071), Mesial to this lies the mandibular knob, which and dermal denticles (UCMP 219036-219054, articulates with the palatoquadrate concavity; 219056-219059, and 219063) from UCMP locali- batoids bear a unique dual quadratomandibu- ties V99833, V99834, V99835, V99840, V99842, lar joint that restricts lateral movement of the V99843, V99844, V99847, and V99854. mandibular arch (Dean & Motta, 2004). The Discussion – Four palatoquadrate cartilages mandibular cartilage is also constructed from and eleven mandibular cartilages were collect- prismatic cartilage, obvious in cross section and ed from the San Gregorio section, in varying abraded portions, and rarely visible along the states of completeness. These are prismatically posterolateral margin of the element. The me- calcified elements, and preserved in bonebeds sial morphology of these elements indicates the alongside bones and teeth as distinct, compe- symphysis was unfused, unlike many extant tent bioclasts; with the exception of cetacean durophagous batoids, such as myliobatids. bones, these elements locally constitute the Among Rajidae that currently inhabit the most abundant type of vertebrate fossil. The temperate northeast Pacific Ocean these - ele palatoquadrate cartilages lack an orbital process ments compare best with those of extant Raja and instead have a labiolingually compressed, binoculata in size and morphology (figures 6.1- tabular-shaped mesial projection, which in 6.2). These elements differ from Dasyatidae by life bore the upper dentition (figures 6.3-6.8). having less robust otic processes and susten- Short ridge-like otic processes occur labially taculi, and comparatively more slender mesial on the dorsolateral margin of the palatoquad- portions of palatoquadrate and mandibular car- rate. The most proximal portion is developed tilages. The genus Rhinobatos exhibits signifi- into a subspherical palatoquadrate condyle, cantly smaller otic processes, and much larger which articulates with the concave mandibular sustentaculi, but lacks such a posterolateral articular fossa (Dean & Motta, 2004). Immedi- projection of the dorsal flange. These elements ately mesial to the commissural process is the differ from those of Myliobatidae and Rhinop- shallow palatoquadrate cavity, which in turn teridae by not having a widely expanded mesial receives the mandibular knob (Dean & Motta, surface with a fused symphysis. This taxon dif- 2004). The palatoquadrate exhibits faintly vis- fers from the genera Torpedo and Gymnura by ible prismatic cartilage, which is often exposed having more robust palatoquadrate and man-

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Figure 6. Cranial elements of modern and fossil Raja from the San Gregorio section of the Purisima Formation. 1-2, UCMP 83662, articulated palatoquadrate and mandibular cartilages of modern Raja binoculata.; 3-4, UCMP 219069, proximal palatoquadrate cartilage of Raja sp., cf. R. binoculata (reversed); 5-6, UCMP 219068, palatoquadrate cartilage of Raja sp., cf. R. binoculata (reversed); 7-8. UCMP 219070, proximal palatoquadrate cartilage of Raja sp., cf. R. binoculata; 9-10, UCMP 219034, complete mandibular cartilage of Raja sp., cf. R. binoculata (reversed); 11-12, UCMP 219022, complete mandibular cartilage of Raja sp., cf. R. binoculata (reversed); 13-14, UCMP 219071, complete mandibular cartilage of Raja sp., cf. R. binoculata. Scale bar is 10 mm.

© PalArch Foundation 16 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) dibular cartilages. Wedgefish and guitarfish tion (F.A. Perry, personal communication, 2006). (Rhinidae) differ from this taxon by exhibiting As only a limited amount of screening was con- laterally expanded sustentaculi and associated ducted at this locality, most microvertebrate dorsal flanges, in addition to subspherical expan- specimens were recovered from the outcrop sions of the tooth pad portion near the symphy- surface, and small specimens like Raja teeth are sis of either element. Mobulidae possess a very easily overlooked. gracile, straight, and extremely labiolingually Fossils of Raja have been reported in Oregon flattened mesial portion of both jaw elements, from the Upper Eocene Nestucca Formation, the differing strongly from these fossil cartilages. Middle Oligocene Pittsburg Bluff Formation, Pristidae have much less robust otic flanges and and the uppermost Oligocene-Lower Miocene sustentaculi than the fossil taxon. Prismatically Nye Mudstone (Welton, 1972). Raja is known calcified mandibular and palatoquadrate carti- in California from the Lower Miocene Jewett lages preserved in this manner have not been Sand (Olson & Welton, 1986), the Upper Mio- reported for any other batoid from the Neogene cene Almejas Formation (Stewart, 1997; Barnes, of the Northeast Pacific. Extensive examination 2008), and from an unnamed Upper Pleistocene of Neogene museum collections (SCMNH, SD- unit near Newport, California (Long, 1993b). NHM, UCMP) have not yielded similar speci- Prismatically calcified palatoquadrate and man- mens from other batoid taxa. dibular cartilages have been observed in mu- Additional elements tentatively referred to seum collections from the Pliocene portion of Raja sp. cf. R. binoculata include a large assort- the Santa Cruz section of the Purisima Forma- ment of dermal denticles or bucklers (figures tion, the Middle Pleistocene Moonstone Beach 5.15-5.22), and are nearly as abundant as the Formation of Humboldt County, California, the calcified cartilage specimens. These denticles Pliocene to Lower Pleistocene Falor Formation are similar to dorsal and ventral ‘bucklers’ of of Humboldt County, California, and the Mid- Rajidae, which have smooth to slightly striated, dle Pleistocene Port Orford Formation of south- conical to disc-shaped osteodentine roots, with western Oregon (Boessenecker, unpublished variously shaped enameloid cusps. The speci- data). Extant Rajidae are small (1-2 m) epiben- mens reported here are disc-shaped, with very thic predators that feed on invertebrates and small enameloid cusps positioned in a slight de- fish and live on continental shelves and slopes; pression just below the level of the rim of the several extant species of Raja inhabit temperate denticles. A hollow cavity in the middle of the waters of the northeast Pacific (Ebert, 2003). denticle is visible when the enameloid cap is missing (figure 5.18). The morphology of these Order Perciformes Bleeker, 1859 elements is very similar to ventral bucklers of Family Scombridae Rafinesque, 1815 Raja clavata (Reynat & Brito, 1994). Addition- Genus Thunnus South, 1845 ally, some specimens (UCMP 219047, 219053, Thunnus sp. and 219063) appear to represent four coalesced denticles (figures 5.19-5.22). The enameloid Figures 7.1-7.2 caps are missing on most of these specimens, and each denticle has taken on a quadrilateral Material examined – One , UCMP shape, and the region of the enameloid cap has 219066, from UCMP locality V99849. migrated toward the center of the element, so Discussion – Tuna vertebrae are rather com- that all four caps abut each other. One speci- mon in some late Neogene deposits (Purdy et al. men (UCMP 219063) is preserved with the caps 2001). However, there are few known from the in place, which bear small, obliquely oriented Purisima Formation. This specimen possesses enameloid spines (figures 5.21-5.22). Similar typical scombrid features including a simple examples of coalesced denticles were described overall morphology, with a single lateral septum from fossil denticles of the stingray that is broadly convex and dorsoventrally thick centroura from the Pliocene of anteriorly and posteriorly, which is somewhat (Purdy et al., 2001). Although no teeth referable narrow and ‘pinched’ toward the middle (figures to this taxon have been identified from this lo- 7.1-7.2). A pair of septa occurs on the dorsal and cality, teeth of Raja sp. have been collected from ventral sides of the centrum, and possesses the the Santa Cruz section of the Purisima Forma- broken bases of the neural and haemal arches.

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Deep fossae occur dorsal and ventral to the lat- other pleuronectiform. Fossils of Paralichthys eral septa. On the anteriormost portion of each have previously been reported from the Up- lateral septum is a small foramen adjacent to per Miocene of Baja California (Stewart, 1997; the broken base of the intramuscular process. Barnes, 2008), and the Pleistocene of southern In anterior and posterior view of extant Thun- California (Long, 1993b). Extant Paralichthys or nus vertebrae and the fossil specimen, the dor- large-tooth flounders are small to medium-sized sal margin of the centrum has a slight concavity (1-1.5 m) epibenthic ambush predators that at the midline (figure 7.1). The scombrid mor- feed on fish and invertebrates, have both eyes phology and the large size of UCMP 219066 on the left side of their body, live in water to identify this specimen as Thunnus. Although 200 m depth on the continental shelf and upper unidentified scombrid fossils were reported by slope. Several species currently live in temper- Stewart (1997) from the Almejas Formation of ate waters of the northeast Pacific (Eschmeyer Baja California, Thunnus has not been reported et al., 1999). from the Neogene of the northeast Pacific, and occurs in the Pliocene of North Carolina (Purdy Class Aves Linnaeus, 1758 et al., 2001). Extant species of tuna are medium Order Sharpe, 1891 sized (1-2 m), epipelagic predators that inhabit Family Sulidae Reichenbach, 1849 tropical and temperate oceans worldwide, and Morus Vieillot, 1816 are among the fastest of all marine vertebrates Morus sp. (Eschmeyer et al., 1999). Figures 8.1-8.2 Order Pleuronectiformes Bleeker, 1859 Family Paralichthyidae Hensley & Ahlstrom, Material examined – UCMP 130134, one left 1984 from UCMP locality V7085. Genus Paralichthys Girard,1858 Discussion – This specimen is a nearly com- Paralichthys sp. plete, well preserved humerus with some minor damage to the proximal end (figures 8.1-8.2). Figures 7.3-7.4 Features that identify this humerus as a (Morus) rather than a booby (Sula) include a Material examined – One vertebra, UCMP- longer deltoid crest than bicipital crest, gradu- 219067, from UCMP locality V99839. ally rounded internal margin of the bicipital Discussion – A single small, partial verte- crest, and an apneumatic olecranon fossa, the bra, exhibits lateral paper-thin septa charac- medial margin of which is not overhanging teristic of Paralichthys, which converge in the (Chandler, 1990). In addition, a large partial middle of the centrum, but diverge anteriorly phalanx (UCMP 219031, figures 8.5-8.6) may and posteriorly; where the septa diverge, deep also be referable to Morus sp. interstitial dossae occur (figure 7.4). Although Morus humeralis and M. recentior have been broken, the centrum exhibits the oval shaped reported from the Plio-Pleistocene San Diego cross section (figure 7.3), which can become Formation by Chandler (1990). The humer- nearly circular or hexagonal in fossil and mod- us of M. humeralis is evidently much smaller ern specimens. Deep fossae occur dorsal and than the San Gregorio specimen. This speci- ventral to the lateral septa. A second specimen men is within the size range of extant Morus (UCMP 219075) is more complete, has a circu- bassanus. Additionally, the much smaller size lar centrum, and a small portion of the base of of the pneumatic opening precludes referral to the neural arch preserved, which appears to be M. humeralis. The large size of this specimen pathologic and swollen, shifting the neural ca- excludes it from all fossil species of Morus ex- nal laterally. Deep recesses occur dorsolaterally, cept M. magnus and M. lompocanus (Chandler, and two lateral septa occur, again with the an- 1990), both of which are known from the Upper teriorly and posteriorly diverging morphology. Miocene Monterey, Sisquoc, and Santa Margar- However, the septa of this specimen are thicker ita Formations of California (Domning, 1978; and exhibit less branching anteriorly and pos- Howard, 1978). Humeri of Morus peninsularis teriorly. This vertebra is tentatively referred differ from this specimen in their smaller size, to Paralichthys, but may actually represent an- and having a deeper brachial fossa. Specific

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Order Charadriformes Huxley, 1867 Family Alcidae Vigors, 1825 Genus Mancalla Lucas, 1902 Mancalla diegensis Miller, 1937

Figures 8.3-8.4

Material examined – One humerus (UCMP 219060) from UCMP locality V99833. Discussion – The robust morphology, shaft curvature, and thick cortex identify this hu- merus as the extinct flightless auk Mancalla. The humeral shaft of Mancalla is dorsoven- trally flattened and laterally broad, and curved medially relative to other Alcidae (figures. 8.3- 8.4). This specimen differs from Praemancalla by having a less compressed shaft and distal end, and a mediolaterally more expanded shaft Figure 7. Vertebrae of teleost fish from the San Gregorio (Howard, 1966). UCMP 219060 differs from section of the Purisima Formation. 1-2, UCMP 219066, vertebral centrum of Thunnus sp. (South, 1845), in anterior Mancalla milleri in its larger size, by possessing and lateral aspect (respectively); 3-4,UCMP 219067, partial a well-developed ligamental attachment on the vertebral centrum of Paralichthys sp. (Girard, 1858), in bicipital crest, and having a more convex dis- anterior (or posterior) and lateral aspect (respectively). tal margin of the bicipital crest, both of which Scale bar is 10 mm. are characteristics of Mancalla diegensis (How- identification of this well-preserved specimen ard, 1970). Unlike Mancalla californiensis, this should await discovery and study of addition- specimen has a straighter shaft and a muscle al humeri of Morus from the late Neogene of scar in the pneumatic fossa with edges that the northeast Pacific. Specimens of Morus have converge anteriorly, as seen in M. diegensis, and previously been collected from the Santa Cruz which are parallel in M. californiensis (Howard, section of the Purisima Formation (F.A. Perry, 1970). Mancalla cedrosensis differs from UCMP personal communication, 2006). Although gan- 219060 in lacking a well developed ligamental nets are extinct in the northeast Pacific Ocean, scar on the bicipital crest, and having a relative- fossils of Morus have been reported from the ly straight distal margin of the bicipital, which middle Miocene Sharktooth Hill Bonebed (Mill- in this specimen (and other M. diegensis) is er, 1961), the Upper Miocene Monterey and Sis- very convex, nearly forming a 90° angle (How- quoc Formations (Miller, 1925; Howard, 1978), ard, 1970; 1971). Additionally, this specimen the Upper Miocene Santa Margarita Sandstone differs from M. cedrosensis by having a more (Domning, 1978), the Upper Miocene Almejas laterally oval-shaped triceps insertion distal to Formation (Howard, 1971), the Middle to Up- the humeral head. This specimen differs from per Pliocene San Diego Formation (Chandler, Mancalla emlongi and a new species of Man- 1990), and from Upper Pleistocene Palos Verdes calla from the Mio-Pliocene Capistrano Forma- Sand (Howard, 1936; Miller, 1971). This find tion and San Mateo Member (of the Capistrano demonstrates that inhabited much of Formation) by its smaller size and less robust the California coast prior to their extirpation morphology. A complete tibiotarsus from the during the Pleistocene. Three species of Morus San Gregorio section (UCMP-219030, figures currently inhabit the Atlantic and the southeast 8.7-8.8) may represent Mancalla diegensis, but Pacific Ocean (Nelson, 1978). Extant gannets is only identified to the family Alcidae. are large, diving that feed on pelagic The large size of the humerus, breadth of fish and breed on rocky shores and islands (Nel- the tricipital insertion, relatively straight shaft, son, 1978). presence of a muscle scar with converging mar- gins within the pneumatic fossa, and a well-de- veloped ligamental attachment on the strongly convex bicipital crest all indicate that this hu-

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Figure 8. Avian bones from the San Gregorio section of the Purisima Formation. 1-2, UCMP 130414, humerus of Morus sp. (Viellot, 1816), in ventral and dorsal aspect (respectively); 3-4, UCMP 219060, humerus of Mancalla diegensis (Miller, 1937), in dorsal and ventral aspect (respectively); 5-6, UCMP 219031, partial phalanx, Aves indet. in dorsal and plantar aspect (respectively); 7-8, UCMP 219030, tibiotarsus of Alcidae indet., in anterior and posterior aspect (respectively). Scale bars = 20 mm. merus is identifiable asMancalla diegensis, pre- habited the northeast Pacific from Baja Califor- viously recorded from the Plio-Pleistocene San nia to northern California during the latest Mio- Diego Formation (Chandler, 1990), the Lower cene, Pliocene, and Pleistocene (Howard, 1970, Pliocene Lawrence Canyon Local Fauna of the 1971, 1982; Kohl, 1974). San Mateo Member of the Capistrano Forma- tion (Howard, 1982), and the Lower Pleistocene Marine Mammals Moonstone Beach Formation (Kohl, 1974). Ad- Abundant bones and teeth of various marine ditional records from the Purisima Formation mammals were collected from the San Gre- include a new large species of mancalline alcid gorio section (representing 13 taxa of marine (N.A. Smith, personal communication, 2008), mammals; table 1), and will be described in a and Mancalla milleri, both from the Santa Cruz separate publication. However, as some of the section of the Purisima Formation. Mancalla marine mammals have implications for the age was a small, penguin-convergent, piscivorous of this deposit (see below) a brief discussion of wing-propelled, flightless diving that in- the mammalian assemblage is pertinent. An

© PalArch Foundation 20 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) unidentified otariid fur seal is represented by sented by the San Gregorio assemblage (table 1). several elements including a tooth, temporal In comparison, nearly 80 taxa have been iden- bone, and some postcrania. An odobenid wal- tified from the Santa Cruz section of the Puri- rus (Dusignathus sp.) is represented by a partial sima Formation, although this higher number radius and isolated vertebrae. Five odontocete is likely due to more intensive collecting and cetaceans are potentially represented by 1) a pooling of multiple assemblages (F.A. Perry and cranium and lower jaws that is congeneric (or R.W. Boessenecker, unpublished data). conspecific) with an undescribed genus and species of bizarre phocoenid from the San Di- Age of the San Gregorio Section ego Formation (Racicot et al., 2007); 2) a partial As outlined above, the precise age of the Puri- skull of a phocoenine ; 3) a tympanic sima Formation west of the San Gregorio Fault of a large, pilot whale-like globicephaline; 4) a has been modified by various researchers over juvenile skull with tympanoperiotics of Para- time. Previous authors (Cummings et al., 1962; pontoporia sp., cf. P. sternbergi and 5) a large Durham & Morgan, 1978; Gavigan, 1984) have squamosal of an possible physeteriod. Mystice- concluded a latest Miocene (ca. 8-5 Ma) age for tes are represented by a large suite of bones and these outcrops based on invertebrate fossils abundant bone fragments, including tympanic from the upper San Gregorio section. Powell bullae of a large balaenid and the smaller right et al. (2007) reported a Late Miocene (6.4-5.6 whale, Balaenula. Balaenopterids are represent- Ma, Nitzchia reinholdii zone) diatom flora from ed by several tympanics of a small balaenopter- the base of the San Gregorio section (figure 2). id, fragments of a very large petrosal, a well pre- However, Sarna-Wocjicki et al. (1991) and Pow- served cranium (Balaenopteridae new species). ell et al. (2007) utilized chemical fingerprinting The bizarre dwarf cetotheriid mysticete Herpet- of ash beds in the Purisima Formation to yield ocetus bramblei is represented by a single, large ash correlations of 3.35-2.5 Ma (figure 2), indica- lower jaw, while a separate taxon (Herpetocetus tive of a Middle Pliocene age. Vertebrate fossils sp.) is represented by two petrosals, a posterior outlined above may help evaluate previously process of a petrosal, a tympanic bulla, and a made age determinations. Many taxa described partial dentary. herein have chronologic ranges that are too long or are too poorly known to be of use; these Discussion include Cetorhinus maximus, cf. Hexanchus, Isurus oxyrinchus, Morus sp., Paralichthys sp., This study reports several first occurrences for Pristiophorus sp., cf. Sphyrna, Squatina sp., and the Purisima Formation. The only previously Thunnus sp.; however, the age implications of recorded non-mammalian marine vertebrates the remaining taxa are discussed below. from this unit are the sharks Isurus hastalis, Fossil teeth of the shark Carcharodon have Carcharodon, Hexanchus, the bat ray , only been reported from the Quaternary, Plio- and the booby Sula, from the Santa Cruz section cene, and latest Miocene. Weakly serrated Car- of the Purisima Formation (Perry, 1977; Stewart charodon teeth are typical of latest Miocene & Perry, 2002). Cetorhinus maximus, Morus sp., and earliest Pliocene strata (Muizon & DeVries, Pristiophorus sp., Raja sp., cf. R. binoculata, and 1985; Stewart & Perry, 2002; Ehret et al., 2009), Squatina sp., constitute new published records while coarsely serrated teeth occur in Pliocene for the Purisima Formation, although unpub- and younger sediments, and are typical of the lished specimens of these taxa are currently extant great white shark, Carcharodon carchari- under study from the Santa Cruz section of as (Muizon & DeVries, 1985; Ehret et al., 2009). the Purisima Formation (F.A. Perry and R.W. The teeth of Carcharodon carcharias described Boessenecker, unpublished data). New records herein (figures 3.7-3.8, 3.12-3.22) have larger for the Purisima (including unpublished mate- serrations than those of latest Miocene Carchar- rial) include Sphyrna sp., Thunnus sp., and Man- odon sp. from Peru (Ehret et al., 2009) and Japan calla diegensis. In addition to these specimens, (Yabe, 2000), as well as Carcharodon teeth from several marine mammals including a fur seal, a the ‘crab marker bed’ in the Santa Cruz section; walrus, , a pilot whale like odontocete, this bed approximates the 5.33 Ma Miocene/ a large odontocete, and four baleen whales oc- Pliocene boundary (Powell et al., 2007). The cur at this locality. Altogether, 26 taxa are repre- teeth reported herein have serrations as large as

© PalArch Foundation 21 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) extant Carcharodon carcharias, as well as Car- San Diego Formation (Deméré & Cerutti, 1982). charodon teeth from the Plio-Pleistocene San Di- Herpetocetus-like fossils (previously identi- ego Formation (Deméré & Cerutti, 1982). There- fied as Nannocetus; Barnes, 1976; Barnes et al., fore, the presence of Carcharodon carcharias 1981) occur in the Upper Miocene (9-6 Ma) San teeth indicates a Middle Pliocene (or younger) Luis Rey River Local Fauna of the San Mateo age for the upper and middle parts of the San Member (of the Capistrano Formation) and Up- Gregorio section. However, the occurrence of a per Miocene (12-10 Ma) Santa Margarita Sand- weakly serrated ‘transitional’ Carcharodon sp. stone (Boessenecker, 2011). This older taxon ex- tooth (figures 3.20-3.22), in concert with a Late hibits different dentary morphology from the Miocene diatom flora, suggests a latest Miocene younger Purisima and San Diego specimens, age for the base of the San Gregorio section. which are morphologically most similar to the Numerous calcified palatoquadrate and Herpetocetus sp. specimen from the San Grego- mandibular cartilages of Raja sp., cf. R. binocu- rio section. Although significantly more work lata were recovered from the San Gregorio sec- is needed for Herpetocetus, this occurrence also tion (figures 5.15-5.22). The only other known indicates a Pliocene age for the San Gregorio occurrences of these cartilaginous cranial ele- section. ments are in Pliocene strata of the Santa Cruz While the longevity of many of the fossil section of the Purisima Formation, the Lower taxa reported herein preclude their usefulness Pleistocene Falor Formation and Moonstone for determining a Late Miocene age or a younger Beach Formation of northern California, and Pliocene age (or otherwise) for the San Gregorio the Middle Pleistocene Port Orford Formation section of the Purisima Formation, several iden- of southwestern Oregon; these all appear to tified above (including Carcharodon, Raja sp., represent one species (Boessenecker, personal cf. R. binoculata, Mancalla diegensis, Phocoeni- observation). Although fossil teeth of Raja are dae new genus, and Herpetocetus sp.) can help known from Eocene through Pleistocene strata elucidate the age relationships of this locality. in western North America (Welton, 1972; Long, Taken in full, these taxa indicate a Pliocene 1993b; Stewart, 1997), these cranial elements age for the upper and middle parts of the San only occur in Middle Pliocene through Lower Gregorio section, and several of these strongly Pleistocene strata in California and Oregon. The indicate a Middle to Late Pliocene age, correla- occurrence of these cranial elements strongly tive with the 4-2 Ma San Diego Formation of indicates a Middle Pliocene to Pleistocene age southern California. This is in accordance with for the upper and middle San Gregorio section. the ash correlation dates for the two tephra The occurrence of the flightless auk Mancalla units (3.35 Ma, and 2.5 Ma) reported by Sarna- diegensis (figures 8.3-8.4) is significant as this Wojcicki et al. (1991) and Powell et al. (2007). taxon is only known from Pliocene and Pleis- While the upper and middle parts of the San tocene sediments of California (see Systematic Gregorio section are most likely Middle to Late Palaeontology). The presence of Mancalla di- Pliocene, the combined presence of a Carcharo- egensis indicates a Middle Pliocene to Pleisto- don sp. tooth with a Late Miocene diatom flora cene age for the upper and middle San Gregorio suggests a somewhat older age for the base of section. the San Gregorio section (figure 2), which is Additionally, undescribed marine mammal also in accordance with the Late Miocene cor- fossils from this locality are also indicative of relations by Cummings et al. (1962), Durham & a Middle to Late Pliocene age. A phocoenid Morgan (1978), and Gavigan (1984). However, it cranium and lower jaw from the San Grego- is important to note that all of the invertebrates rio section is congeneric with a new genus re- examined by these authors were collected from cently reported by Racicot et al. (2007) from the the upper and middle parts of the San Gregorio Plio-Pleistocene (4-2 Ma) San Diego Formation. section, herein determined to be Middle Plio- A dentary and several periotics and tympanics cene or younger. Interestingly, Gavigan (1984) of Herpetocetus sp. are also from this locality. correlated the San Gregorio section with the Similar fossils (Herpetocetus bramblei, Herpe- Falor Formation which was then considered to tocetus sp.) occur in the ‘crab marker bed’ and be Late Miocene; the Falor Formation is now younger strata (5.3-3.5 Ma; Pliocene) in the known to be latest Pliocene and Pleistocene in Santa Cruz section and the Pliocene/Pleistocene age (Nilsen & Clarke, 1989). The invertebrate

© PalArch Foundation 22 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011) assemblages and correlations of Durham & ica and one of the youngest pelagornithid fos- Morgan (1978) and Gavigan (1984) should be sils worldwide, and adds another taxon to the investigated further, and reevaluated in light San Gregorio assemblage, bringing the total to of modern advances in biostratigraphy of Neo- 27. The second article is Smith (2011), which gene marine strata in California. included a taxonomic revision of mancalline auks from California, and descriptions of sev- Conclusions eral new species of Mancallinae. The holotype of Mancalla diegensis is a femur, and because The Purisima Formation near Halfmoon Bay, alcid femora are not diagnostic to the species California, has yielded a diverse assemblage of level, Smith (2011) considered this taxon to be 26 taxa, including sharks (Carcharodon carcha- Pan-Alcidae incertae sedis. A new species, Man- rias, Carcharodon sp., Cetorhinus maximus, cf. calla lucasi, was erected for diagnostic material Hexanchus, Isurus oxyrhincus, Pristiophorus sp., formerly referred to Mancalla diegensis (Smith, cf. Sphyrna, Squatina sp.) skates (Raja sp., cf. 2011), and the fossil specimen identified above R. binoculata), bony fish Paralichthys( sp., Thun- as Mancalla diegensis should now be regarded nus sp.), birds (Mancalla diegensis, Morus sp.), as a referred specimen of Mancalla lucasi. and marine mammals including pinnipeds and cetaceans. A Late Miocene age for this locality Acknowledgements was previously proposed based on lithologic correlations and supported by early molluscan I would like to thank the editor (B. Beatty) and biostratigraphy, while a Middle to Late Plio- two anonymous reviewers for comments which cene age was indicated by ash correlations. The substantially improved the quality of this arti- stratigraphic range of some of these vertebrate cle. Invaluable assistance in the field, laboratory, taxa supports a Middle to Late Pliocene age for and correspondence from F. Perry (SCMNH) is the upper and middle parts of the San Gregorio greatly appreciated. I extend sincere thanks to section, supporting the ash correlations. How- my advisor, D.J. Varricchio (MSU), who offered ever, the presence of Carcharodon sp. in concert encouragement, funding, administrative guid- with a diatom flora at the base of this section ance, and patience. I am grateful to C. Powell indicates a Late Miocene to Early Pliocene age II, who reviewed several earlier drafts of this for the lower part of the San Gregorio section. manuscript, substantially improving its quality. In this study, the utilization of the vertebrate I would like to thank the following, who assisted assemblage to evaluate the age of these strata me in the field and laboratory: C. Ancell (MOR), demonstrates that both the biostratigraphic C. Argento, B. Baziak (MOR), A. Beerman, M. and tephrochronologic age determinations are Berrini, J. Horner (MOR), R. Hua (MSU), V. correct. Future studies utilizing a holistic ap- Jacklich, J. Jette (MOR), L. Johnson (NCSU), S. proach to other vertebrate assemblages may Michalies (MSU), E. Morschauser (MSU), C. Pir- help resolve age determinations for other Neo- rone, C. Powell II (Menlo Park USGS), C. Wood- gene marine deposits in California. ruff (MSU), and especially T. Palladino. Access to museum collections was facilitated by D. Note Added In Proof Catania (CAS), J. Demouthe (CAS), P. Holroyd (UCMP); D.J. Long (OMC), F.A. Perry (SCMNH), During the period in which this article was in and K. Randall (SDNHM). This study benefited review, two studies relevant to this article have from discussions with J. Bourdon, T. Deméré been published (or accepted for publication). (SDNHM), D. Ehret (UF), D. Fowler (MOR), M. Both of these studies concern fossil birds of Gottfried (UM), F. Perry (SCMNH), C. Powell II the San Gregorio vertebrate assemblage, or the (Menlo Park USGS), R. Purdy (USNM), N. Py- of the bird fossils reported herein. enson (USNM), J. Scanella (MOR), J. Schmitt The first is Boessenecker & Smith (In press), (MSU), K. Shimada (UI), N.A. Smith (UT), and which reports a large humerus of a gigantic D. Varricchio (MSU). I would like to thank L. bony-toothed bird, sp. The fossil was Hall (MSU), F. Perry (SCMNH), C. Powell II, properly identified after this article was submit- (Menlo Park USGS), J. Scannella (MOR), N.A. ted for publication. This fossil represents one Smith (UT), and D. Varricchio (MSU), who com- of the largest flying birds ever in North Amer- mented on early versions of this manuscript.

© PalArch Foundation 23 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

The coordination of the California State Parks Barnes, L.G., H. Howard, J.H. Hutchison & and the collections permit application process, B.J. Welton. 1981. The vertebrate fossils of through S. Brown, J. Kerbavez, and the Rang- the marine San Mateo Formation er-Lifeguards at Half Moon Bay State Beach, at Oceanside, California. In: Abbott P.L. & is greatly appreciated. Funding was provided S. O’Dunn. Eds. 1981. Geologic investiga- by Montana State University Undergraduate tions of the San Diego coastal plain. – San Scholars Program. Diego, San Diego Association of Geologists, California: 53-70. Cited Literature Berg, L.S. 1940. Classification of fishes both recent and fossil. – Traveux de l’Institut Arnold, R. & H. Hannibal. 1913. The marine Ter- Zoologique de l’academie des Sciences de tiary stratigraphy of the North Pacific Coast l’U.R.S.S., Leningrad 5: 85-517. of America. – Proceedings of the American Berg, L.S. 1958. System der Rezenten und fos- Philosophical Society 52: 559-605. silien Fischartigen und Fische. – Berlin, Ger- Ashby, J.R. & J.A. Minch. 1984. The Upper Plio- many (Hochschulbucher fur Biologie). cene San Diego Formation and the occur- Blainville, de, H.M.D. 1816. Prodrome d’une rence of Carcharodon megalodon at La Joya, distribution systématique du regne . , Baja California, . In: Minch – Bulletin des Sciences par la Socie´te´ Philo- J.A. & J.R. Ashby. Eds. 1984. Miocene and Cre- matique de Paris 8: 105-124. taceous depositional environments, North- Bleeker, P. 1859. Enumeratio specierum piscium western Baja California, Mexico. – Pacific Sec- hucusque in Archipelago indico observata- tion A.A.P.G., Los Angeles, California: 19-28. rum, adjectis habitationibus citationibusque, Aubry, M.P., W.A. Berggren, J. Van Couvering, B. ubi descriptiones earum recentiores reperi- McGowan, F. Hilgen, F. Steininger & L. Lou- untur, nec non speciebus Musei Bleekeriani rens. 2009. The Neogene Quaternary: chro- Bengalensibus, Japonicis, Capensibus Tas- nostratigraphic compromise or nonoverlap- manicisque. – Acta Societatis Scientiarum ping magisteria? – Stratigraphy 6: 1-16. Indo-Neerlandae 6: 1-276. Barnes, L.G. 1976. Outline of eastern Northeast Boessenecker, R.W. 2006. A new marine ver- Pacific fossil cetacean assemblages. – System- tebrate assemblage from the late Neogene atic Zoology 25: 321-343. Purisima Formation at Pomponio State Barnes, L.G. 1985. Fossil pontoporiid Beach. – Journal of Vertebrate , (Mammalia: ) from the Pacific coast 26 (Supplement to number 3): 43A. of North America. – Los Angeles County Mu- Boessenecker, R.W. 2011. Herpetocetine (Ce- seum Contributions in Science 363: 1-34. tacea: Mysticeti) dentaries from the Upper Barnes, L.G. 1991. The fossil marine vertebrate Miocene Santa Margarita Sandstone of Cen- fauna of the latest Miocene Almejas Forma- tral California. – Paleobios 30: 1-12. tion, Isla Cedros, Baja California, México. In: Boessenecker, R.W. & J.H. Geisler. 2008. New Carrillo-Chávez A. & A. Alvarez-Arellano. Eds. material of the bizarre whale Herpetocetus 1991. Primera reunión internacional sobre bramblei from the latest Miocene Purisima geología de la Península de Baja California. Formation of Central California. – Journal of Memorias. – Universidad Autónoma de Baja Vertebrate Paleontology 28 (Supplement to California Sur, La Paz, Baja California Sur, number 3): 54A. México: 147-166. Boessenecker, R.W. & F.A. Perry. In press. Mam- Barnes, L.G. 2008. Miocene and Pliocene Albir- malian bite marks on juvenile fur seal bones eonidae (Ceatcea, Odontoceti), rare and un- from the late Neogene Purisima Formation usual fossil dolphins from the Eastern North of Central California. – Palaios. Pacific Ocean. – Natural History of Los Ange- Boessenecker, R.W. & N.A. Smith. In press. Lat- les County Science Series 41: 99-152. est Pacific basin record of a bony-toothed bird Barnes, L.G. & F.A. Perry. 1989. A toothless walrus (Aves, ) form the Pliocene from the Purisima Formation in California, Purisima Formation of California, U.S.A. – U.S.A. Abstracts, Eighth Biennial Conference Journal of Vertebrate Paleontology 31. on the Biology of Marine Mammals. – Pacific Boessenecker, R.W., J.H. Geisler & F.A. Perry. Grove, California, December, 1989, 8: 5. 2009. A fossil pilot whale, Globicephala sp.

© PalArch Foundation 24 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

(Cetacea: Delphinidae) from the Late Plio- Miles & C. Patterson. Eds. 1973. – Zoological cene Purisima Formation of central Califor- Journal of the Linnean Society, Supplement nia. – Journal of Vertebrate Paleontology 29 no. 1 to volume 53: 15-98. (Supplement to number 3): 66A. Compagno, L.J.V. 1984. FAO species catalogue. Bonaparte, C.L. 1832-1841 [1838]. Iconografia Sharks of the world. An annotated and illus- della Fauna Italica, per le Quattro Classi de- trated catalogue of shark species known to gli Animali Vertebrati. 3 (Peschi). – Rome, date. – Rome, Food and Agriculture Organi- Tipographia Salviucci. zation of the United Nations. Bonner W.H. & W.B. Gilmour. 1988. The Rem- Compagno, L.J.V., M. Dando & S. Fowler. 2005. ington whales: analysis of two Late Miocene Sharks of the world. – Princeton, Princeton Mysticeti from Orange County, California. – University Press. Southern California Paleontological Society Cummings, J.C., R.M. Touring & E.E. Brabb. Special Publication 6: 1-49. 1962. Geology of the northern Santa Cruz Buen, de, F. 1926. Catálogo ictiológico del Medi- Mountains. – California Division of Mines terráneo español y de Marruecos recopi- Geology Bulletin 181: 179-220. lando lo publicado sobre peces de las costas Dean, M.N. & P.J. Motta. 2004. Anatomy and mediterranea y próximas del Atlántico (Mar functional morphology of the feeding appa- de España). – Resultado de las campañas re- ratus of the lesser electric ray, Narcine brasil- alizadas por acuerdos internacionales bajo la iensis (: Batoidea). – Journal dirección del Prof. O. de Buen. 2: 1-221. of Morphology 262: 462-483. Cappetta, H. 1987. Vol. 3B. Chondrichthyes II, Deméré, T.A. & R.A. Cerutti. 1982. A Pliocene Mesozoic and Cenozoic Elasmobranchii. on a cetotheriid whale. – Jour- In: Schultze, H.P. Ed. 1987. Handbook of nal of Paleontology 56: 1480-1482. Paleoichthyology. – Gustav Fisher Verlag, Deméré, T.A., M.A. Roeder, R.M. Chandler & Stuttgart. J.A. Minch. 1984. Paleontology of the Middle Cappetta, H. 2006. Fossilium catalogus I: Ani- Miocene Los Indios Member of the Rosarito malia, pars 142. Elasmobranchii Post-Triadi- Beach Formation, Northwestern Baja Califor- ci (Index specierum et generum). – Bakhuys, nia, Mexico. In: Minch, J.A. & J.R. Ashby. Eds. Leiden. 1984. Miocene and Cretaceous depositional Chandler, R.M. 1990. Fossil birds of the San environments, Northwestern Baja Califor- Diego Formation. – Ornithological Mono- nia, Mexico. – Pacific Section A.A.P.G., Los graphs 44: 73-161. Angeles, California: 47-56. Cione, A. & M. Reguero. 1998. A Middle Eocene Domning, D.P. 1978. Sirenian evolution in the basking shark (Lamniformes, Cetorhinidae) North Pacific Ocean. – University of Califor- from Antarctica. – Antarctic Science 10: 83-88. nia Publications in Geological Sciences 18: Clark, J.C. 1966. Tertiary stratigraphy of the Fel- 1-176. ton-Santa Cruz area, Santa Cruz Mountains, Dumeril, A.M.C. 1806. Zoologie analytique ou California. – Unpublished Ph.D. Dissertation methode naturelle de classification animaux. Stanford University. – Paris, Allais. Clark, J.C., & E.E. Brabb. 1978. Stratigraphic Durham, J.W. & S.R. Morgan. 1978. New sand contrasts across the San Gregorio Fault, San- dollars (Echinoidea) of the genera Merria- ta Cruz Mountains, West-central California. master and Dendraster from Purisima For- – California Division of Mines and Geology mation, California. – Proceedings of the Special Report 137: 3-12. California Academy of Sciences 41: 297-305. Clark, J.C., E.E. Brabb, H.G. Greene & D.C. Ross. Ebert, D.A. 2003. Sharks, rays, and chimae- 1984. Geology of Point Reyes Peninsula and ras of California. – Berkeley, University of implications for San Gregorio Fault history. California Press (California Natural History In: Crouch J.K. & S.B. Bachman. Eds. 1984. Guides). Tectonics and sedimentation along the Cali- Ehret, D.J., G. Hubbell & B.J. MacFadden. 2009. fornia margin. – Pacific Section SEPM, Los Exceptional preservation of the white shark Angeles, California 38: 67-86. Carcharodon (Lamniformes, Lamnidae) Compagno, L.J.V. 1973. Interrelationship of liv- from the early Pliocene of Peru. – Journal of ing elasmobranchs. In: Greenwood, P.H., R.S. Vertebrate Paleontology 29: 1-13.

© PalArch Foundation 25 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

Eschmeyer, W., E. Herald & H. Hammann. 1999. Gottfried, M.D. & J.A. Rabarison. 1997. First A field guide to the Pacific coast fishes of Mesozoic Gondwanan record of a sawshark North America. – Peterson Field Guides, Bos- (Chondrichthyes, Pristiophoriformes), from ton. the Late Cretaceous of . – Journal Fitzgerald, E.M.G. 2004. A review of the Tertiary of Vertebrate Paleontology 17: 750-751. fossil Cetacea (Mammalia) localities in Aus- Gradstein, F.M., Ogg, J.G. & A.G. Smith. Eds. tralia. – Memoirs of the Museum of Victoria 2004. A geologic timescale 2004. – Cam- 61: 183-208. bridge University Press. Galloway, A.J. 1977. Geology of the Point Reyes Gray, J.E. 1851. List of the specimens of fish in Peninsula, Marin County, California. – the collection of the British Museum, part 1. California Division of Mines and Geology – London, British Museum of Natural His- Bulletin 202: 1-72. tory. Gavigan, C.L. 1984. Composition and stratigra- Gunnerus, J.E. 1765 (1767). Brugden (Squa- phy of the Purisima Formation in the central lus maximus), Beskrivenen Gunnerus. – California Coast Ranges. – Unpublished M.S. Beskrevnen ved. Norway, Kongelige norske Thesis California, Stanford University. Videnskabers selskab Skrifter Trondheim 3: Gibbard, P.L., M.J. Head, M.J. Walker and the 33-49. Subcommission on Quaternary Stratigraphy. Haehl, H.L. & R. Arnold. 1904. The Miocene 2009. Formal ratification of the Quaternary diabase of the Santa Cruz Mountains in San System/Period and its Pleistocene series/ep- Mateo County, California. – American Philo- och with a base at 2.58 Ma. – Journal of Qua- sophical Society Proceedings 43: 16-53. ternary Science 25: 96-102. Hensley, D.A. & E.H. Ahlstrom, 1984. Pleuronec- Gill, T. 1862. Analytical synopsis of the Order of tiform relationships. In: Moser H.G., W.J. Squali and revision of the nomenclature of Richards, D.M. Cohen, M.P. Fahay, A.W. Ken- the genera: Squalorum Generum Novorum dall & S.L. Richardson. Eds. 1984. Ontogeny Descriptiones Diagnosticae. – Annals of Ly- and systematics of fishes. – Lawrence, Allen ceum of Natural History of New York 7, 32: Press: 670-687. 367-413. Herman, J. 1979. Réflexions sur la systématique Gill, T. 1872 (1862). On the classification of the des Galeoidei et sur les affinités du genre families and genera of the Squali of Califor- Cetorhinus à l’occasion de la découverte nia. – Proceedings of the National Academy d’éléments de la denture d’un exemplaire of Sciences 14: 483-501. fossile dans les sables du Kattendijk à Kallo Girard, C.F. 1855. Characteristics of some carti- (Pliocène Inférieur, Belgique). – Annales de laginous fishes of the Pacific coast of North la Société Géologique de Belgique 102: 357- America. – Proceedings of the Academy of 377. Natural Sciences of Philadelphia 7: 196-197. Howard, H. 1929. The avifauna of the Emeryille Girard, C.F. 1858. Fishes. – Reports of explo- shellmound. – University of California Pub- rations and surveys, to ascertain the most lications in Zoology 32, 2: 301-394. practicable and economical route for a rail- Howard, H. 1936. A new fossil bird locality near road from the Mississippi River to the Pa- Playa del Rey, California, with a description cific Ocean 10: 1-400. of a new species of sulid. – The Condor 38: Glen, W. 1959. Pliocene and lower Pleistocene of 211-214. the western part of the San Francisco penin- Howard, H. 1966. A possible ancestor of the sula. – University of California Publications Lucas Auk (Family Mancallidae) from the in Geological Sciences 36: 147-198. Tertiary of Orange County, California. – Los Goodwin, M., T. Deméré, P. Holroyd, R. Wilson Angeles County Museum Contributions in & S. Dowker. 2009. Unusual preservation of Science 101: 1-8. fossil baleen (Cetacea: Mysticeti) from the Howard, H. 1970. A review of the extinct avian Miocene of California, USA: comparative genus, Mancalla. – Los Angeles County Mu- morphology and stable isotope evidence for seum Contributions in Science 203: 1-12. seasonality and growth. – Journal of Verte- Howard, H. 1971. Pliocene avian remains from brate Paleontology 29 (Supplement to num- Baja California. – Los Angeles County Mu- ber 3): 107A. seum Contributions in Science 217: 1-17.

© PalArch Foundation 26 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

Howard, H. 1978. Late Miocene marine birds chii) of New Zealand and Australia, with a from Orange County, California. – Los An- review of the phylogeny and distribution geles County Museum Contributions in Sci- of world fossil and extant Pristiophoridae. ence 290: 1-26. – New Zealand Journal of Geology and Geo- Howard, H. 1982. Fossil birds from Tertiary ma- physics 25: 459-474. rine beds at Oceanside, San Diego County, Kohl, R.F. 1974. A new Late Pleistocene fauna California, with descriptions of two new spe- from Humboldt County, California. – The cies of the genera Uria and Cepphus (Aves: Veliger 17: 211-219. Alcidae). – Los Angeles County Museum Kuga, N. 1985. Revision of Neogene mackerel Contributions in Science 341: 1-15. shark of genus Isurus from Japan. – Memoirs Howard, H. & L.G. Barnes. 1987. Middle Mio- of the Faculty of Science, Kyoto University, cene marine birds from the foothills of the Series of Geology and Mineralogy 51: 1-20. Santa Ana Mountains, Orange County, Cali- Leidy, J. 1868. Notice of some extinct cetaceans. fornia. – Los Angeles County Museum Con- – Proceedings of the Philadelphia Academy tributions in Science 383: 1-9. of Natural Sciences 1868: 196-197. Huxley, T.H. 1867. On the classification of birds: Linnaeus, C. 1758. Systema naturae. Vol.1. and on the taxonomic value of the modifica- Regnum animale. – Stockholm, Laurentius tions of certain of the cranial bones observ- Salvius. able in the class. – Proceedings of the Zoo- Long, D.J. 1992. Sharks from the La Meseta For- logical Society of London 10: 415-472. mation (Eocene), Seymour Island, Antarctic Huxley, T.H. 1880. On the application of the Peninsula. – Journal of Vertebrate Paleontol- laws of evolution to the arrangement of ogy 12: 11-32. the vertebrata and more particularly of the Long, D.J. 1993a. Late Miocene and Early Plio- mammalia. – Zoological Society of London cene fish assemblages from the north central 43: 649-662. coast of . – Tertiary Research 14: 117- Jordan, D.S. 1907. The fossil fishes of California, 126. with supplementary notes on other species Long, D.J. 1993b. Preliminary list of the marine of extinct fishes. – University of California fishes and other vertebrate remains from the Bulletin of the Department of Geology 5: 95- Late Pleistocene Palos Verdes Sand Forma- 144. tion at Costa Mesa, Orange County, Califor- Kellogg, R. 1927. Fossil pinnipeds from Califor- nia. – PaleoBios 15: 9-13. nia. – Carnegie Institute of Washington Con- Lucas, F.A. 1902. A flightless auk,Mancalla cali- tributions to Paleontology 348: 25-37. forniensis, from the Miocene of California. Kemp, N.R. 1978. Detailed comparisons of the – Proceedings of the National dentitions of extant hexanchid sharks and Museum 24: 133-134. Tertiary hexanchid teeth from South Aus- Madrid, V.M., R.M. Stuart & K.L. Verosub. 1986. tralia and Victoria (Selachii: Hexanchidae). Magnetostratigraphy of the late Neogene – Memoirs of the National Museum of Vic- Purisima Formation, Santa Cruz County, toria 39: 61-83. California. – Earth and Planetary Science Kemp, N.R. 1991. Chondrichthyans in the Creta- Letters 79: 431-440. ceous and Tertiary of Australia. In: Vickers- Miller, L.H. 1925. Avian remains from the Mio- Rich, P., J. Monaghan, R. Baird & T. Rich. Eds. cene of Lompoc, California. – Carnegie In- 1991. Vertebrate palaeontology of Austral- stitution of Washington Publication 349: asia. – Melbourne, Pioneer Design Studio/ 107-117. Monash University Publications Committee: Miller, L.H. 1937. An extinct puffin from the 497-568. Pliocene of San Diego, California. – Trans- Keyes, I.W. 1979. Ikamauius, a new genus of actions of the San Diego Society of Natural fossil sawshark (Order Selachii: Family Pris- History 8: 375-378. tiophoridae) from the Cenozoic of New Zea- Miller, L.H. 1961. Birds from the Miocene of land. – New Zealand Journal of Geology and Sharktooth Hill, California. – The Condor Geophysics 22: 125-129. 63: 399-402. Keyes, I.W. 1982. The Cenozoic sawshark Pris- Mitchell, E.D. 1961. A new walrus from the Im- tiophorus lanceolatus (Davis) (Order Sela- perial Pliocene of southern California, with

© PalArch Foundation 27 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

notes on odobenid and otariid humeri. – Los phometric analyses of fossil teeth. – Journal Angeles County Museum Contributions in of Vertebrate Paleontology 26: 806-814. Science 44: 1-28. Olson, H.C. & B.J. Welton. 1986. Foraminifera Miller, W.E. 1971. Pleistocene vertebrates of the and fishes of Tertiary units in the Bakers- Los Angeles basin and vicinity (exclusive of field, California area. In: Bell, P. Ed. 1986. Rancho La Brea). – Bulletin of the Los Ange- Guidebook Pacific Section AAPG meeting, les County Museum of Natural History Sci- 1986. – Bakersfield, California: 47-49. ence 10: 1-124. Packard, E.L. 1962. Fossil marine mammals Mitchell, E.D. 1962. A walrus and a sea lion from from the vicinity of Stanford University. – the Pliocene Purisima Formation at Santa Journal of Paleontology 36: 29-37. Cruz, California: with remarks on the type Perry, F.A. 1977. Fossils of Santa Cruz County. locality and geologic age of Dusignathus san- – Santa Cruz, Santa Cruz Museum Associa- tacruzensis Kellogg. – Los Angeles County tion. Museum Contributions in Science 56: 1-24. Perry, F.A. 1989. Fossil invertebrates and geol- Mitchell, E.D. 1965. History of research at Shark- ogy of the marine cliffs at Capitola, Califor- tooth Hill, Kern County, California. – Bakers- nia: Santa Cruz, California. – Santa Cruz, field, Kern County Historical Society. Santa Cruz Museum Association. Mitchell E.D. & R.H. Tedford. 1973. The Ena- Perry, F.A. 1993. Fossil sharks and rays of the liarctinae, a new group of extinct aquatic Southern Santa Cruz Mountains, California. Carnivora and a consideration of the origin – Santa Cruz, Santa Cruz Museum Associa- of the Otariidae. – Bulletin of the American tion. Museum of Natural History 151: 201-284. Phillips, F.J., B.J. Welton & J. Welton. 1976. Pa- Muizon, de, C. & T.J. DeVries. 1985. Geology and leontologic studies of the middle Tertiary paleontology of late Cenozoic marine depos- Skooner Gulch and Galloway Formations its in the South Pacific (Sacaco area, Peru). at Point Arena, California. In: Fritsche A.E., – Geologische Rundschau 74: 547-563. H. Ter Best & W.W. Wornhardt. Eds. 1976. Müller, J. & F.G.J. Henle. 1837. Hr. Muller The Neogene symposium; selected techni- las über die ‘gattungen der Haifische and cal papers on paleontology, sedimentology, Rochen’, nach einer von ihm mit Hrn. Henle petrology, tectonics and geologic history of unternommenen gemeinschaftlichen arbeit: the Pacific Coast of North America. – Society ‘über die naturgeschichte der knorpelfische’. for Economic Paleontologists and Mineralo- – Berichte über die zur Bekanntmachung gists: 137-154. geeigneten der K. Preuss Akademie der Wis- Powell, II, C.L. 1998. The Purisima Formation senschaften zu Berlin 2: 111-118. and related rocks (Upper Miocene- Pliocene), Müller, J. & F.G.J. Henle. 1838. On the generic greater San Francisco Bay Area, Central Cali- characters of cartilaginous fishes, with - de fornia. Review of literature and USGS col- scriptions of new genera. – Magazine of Nat- lection (now housed at the Museum of Pale- ural History 2: 1-91. ontology, University of California, Berkeley). Nakano, Y. 1999. Middle Miocene selachian fau- – US Geological Survey Open File Report na of the Fujina Formation, Shimane Prefec- 98-594. ture, West Japan. – Bulletin of the Mizunami Powell, II, C.L., J.R. Allen & P.J. Holland. 2004. In- Fossil Museum 26: 141-148. vertebrate paleontology of the Wilson Grove Nelson, J.B. 1978. The gannet. – Berkhamstead, Formation (late Miocene to late Pliocene), T & A.D. Poyter. Sonoma and Marin Counties, California, Nilsen, T.H. & S.H. Clarke. 1989. Late Cenozoic with some observations on its stratigraphy, basins of Northern California. – Tectonics 8: thickness, and structure. – US Geological 1137-1158. Survey Open File Report 2004-1017. Norris, R.D. 1986. Taphonomic gradients in Powell, II, C.L., J.A. Barron, A.M. Sarna-Wojcicki, shelf fossil assemblages: Pliocene Purisima J.C. Clark, F.A. Perry, E.E. Brabb & R.J. Fleck. Formation, Calfornia. – Palaios 1: 256-270. 2007. Age, stratigraphy, and correlation of Nyberg, K.G., C.N. Ciampaglio & G.A. Wray. the late Neogene Purisima Formation, cen- 2006. Tracing the ancestry of the great white tral California coast ranges. – U.S. Geological shark, Carcharodon carcharias, using mor- Survey Professional Paper 1740.

© PalArch Foundation 28 Boessenecker, California’s Purisma Formation Part I PalArch’s Journal of Vertebrate Palaeontology, 8(4) (2011)

Prothero, D.R., J.N. Lau & J.M. Armentrout. 1991. Quaternary nonglacial geology: con- 2001. Magnetic stratigraphy of the upper terminous U.S. – Boulder, Geological Society Miocene (Wishkahan) Empire Formation, of America: 117-140. Coos County, Oregon. In: Prothero, D.R. Ed. Sharpe, R.B. 1891. A review of recent attempts 2001. Magnetic stratigraphy of the Pacific to classify birds. In: Hungarian Committee Coast Cenozoic. – Los Angeles, Pacific Sec- of 11 International Congress. Proceedings tion of Society of Economic Paleontologists of the International Ornithological Congres. and Mineralogists: 284-292 (Pacific Section, – Budapest, International Ornithological SEPM, Los Angeles, California, Special Pub- Congress. lication 91). Shimada, K. 2002. Dentition of the modern Purdy, R.W., V.P. Schneider, S.P. Applegate, basking shark, Cetorhinus maximus (Lamni- J.H. McLellan, R.L. Meyer & B.H. Slaughter. formes: Cetorhinidae), and its paleontologi- 2001. The Neogene sharks, rays and bony cal and evolutionary implications. – Journal fishes from the lee creek mine, Aurora, of Fossil Research 35: 1-5. North Carolina. In: Ray C.E. & D.J. Bohas- Smith, N.A. 2011. Taxonomic revision and phy- ka. Eds. 2001. Geology and paleontology of logenetic analysis of the flightless Mancalli- the Lee Creek Mine, North Carolina, III. – nae (Aves, Pan-Alcidae). – ZooKeys 91: 1-116. Smithsonian Contributions to Paleobiology South, J.F. 1845. Thunnus. In: Smedley E., Rose 90: 71-202. H.J. & H.J. Rose Eds. 1845. Encyclopedia met- Pyenson, N.D. & K. Brudvik. 2007. Rare fossil ba- ropolitana. – London, Taylor: 620-622. leen from the Purisima Formation of Califor- Stewart, J.D. 1997. New late Miocene fishes from nia: implications for soft tissue preservation the Almejas Formation of Cedros Island, in shallow marine environments. – Journal Baja California. – Memorias of the Fourth of Vertebrate Paleontology 27 (supplement International Meeting on Geology of the to number 3): 132A. Baja California Peninsula. (Unpaginated). Racicot, R., T.A. Deméré & T. Rowe. 2007. Mor- Stewart, J. D. & F.A. Perry. 2002. First paleomag- phology of a bizarre new fossil porpoise (Ce- netic framework for Isurus-Carcharodon tacea: Phocoenidae) from the Pliocene San transition in the Pacific basin: the Purisima Diego Formation of Southern California, Formation, Central California. – Journal of USA. – Journal of Vertebrate Paleontology, Vertebrate Paleontology 22 (supplement to 27 (supplement to number 3): 132A. number 3): 111A. Rafinesque, C.S. 1810. Caratteri di alcuni nuovi Stewart, J.D. & R. Raschke. 1999. Correlation of generi e nuove specie di animali e piante stratigraphic position with Isurus-Carchar- delta Sicilia. – Palermo, Nessuno. odon tooth serration size in the Capistrano Rafinesque, C.S. 1815. Analyse de la nature ou Formation, and its implications for the an- tableau de l’univers et des corps organisés. – cestry of Carcharodon carcharias. – Journal Palermo, Giovanni Barravecchia. of Vertebrate Paleontology 19 (supplement Reichenbach, H.G.G. 1849. Avium systema to no. 3): 78A. naturale. Das natürliche system der Vögel. – Vanderhoof, V.L. 1951. History of geologic in- Dresden and Leipzig, Hofmeister. vestigations in the Bay Region. – California Repenning, C.A. & R.H. Tedford. 1977. Otarioid Division of Mines Bulletin 154: 109-116. seals of the Neogene. – United States Geo- Vieillot, L.J.P. 1816. Analyse d’une nouvelle or- logical Survey Professional Paper 992: 1-93. nithologie élémentaire. – Paris, d’Éterville. Reynat, P.P. & P.M. Brito. 1994. Révision des tu- Vigors, N. 1825. Observations on the natural af- bercules cutanés de raies (Chondrichthyes, finities that connect the families of birds. – Batoidea) du basin du Paraná, Tertiaire Transactions of the Linnaean Society of Lon- d’Amérique du Sud. – Annales de Paleon- don 14: 395-517. tologie 1994: 237-251. Welton, B.J. 1972. Fossil sharks in Oregon. – The Sarna-Wojcicki, A.M., K.R. Lajoie, C.E. Meyer, Ore Bin 34: 161-170. D.P. Adam & H.J. Rieck. 1991. Tephrochrono- Welton, B.J. 1974. A preliminary note on the Pa- logic correlation of upper Neogene sedi- leocene elasmobranchs of the Lodo Forma- ments along the Pacific margin, contermi- tion, Fresno County, California. In: Payne, M. nous United States. In: Morrison, R.B. Ed. & G.R. Hornaday. Eds. 1974. The

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