Although lying in the shadows of the Cretaceous selachian publications on Texas and Kansas, New Mexico has a rich history extending back to Gibbes (1849) who reported on the Scapanorhynchus texanus tooth-design under the name Lamna contortidens. The accompanying Early Santonian selachian assemblage, from less than an acre (largely < two square meters), in New Mexico is more diverse than all the chalk of Kansas and/or Santonian reports from Texas; and, roughly equal to the entire Santonian of Texas and the Gulf states as reported by Meyer (1974) and Case et al (2001). Many unturned stones remained in this study -- a paleo-opportunity for a student in the future.

Material. Less than 100 kg of matrix was removed from the fossiliferous bone bed and backpacked from the site. Using repetitive drying and washing, this matrix was gradually reduced and captured in screens (smallest = .6 mm). The material was highly fractured and most specimens did not survive the primary washing. Various methods of additional cleaning were employed (chemical and mechanical) when possible. Ultimately, the sample yielded 9000+ specimens — ~7000 selachian.
Although a few specimens (Onchosaurus rostral spine and a Ptychodus tooth) from an earlier study (Williamson et al, 1989) were included below; the remainder is from the recent study (Bourdon et al, 2011). Material is in the collection of the New Mexico Museum of Natural History and Science.

Stratigraphy and depositional environment. The Hosta Tongue of the Point Lookout Formation represents shallow waters of a beach-like environment with riverine elements; it has been interpreted as Early to Middle Santonian, roughly equivalent in age the Eutaw Formation of the Gulf Coast and portions of the Kansas chalk.

Assemblage. The collected bone bed is made-up of marine vertebrates, largely shark teeth, denticles & rostral spines and teleost teeth & vertebrae. Marine reptiles (Figs. & ) are sometimes present as are terrestrial components such as dinosaurs (Figs. & ). Teleost material is rather typical with large numbers of small vertebrae (Figs. c,f,g) and non-descript crushing teeth (Fig. i); but also teeth or scales typically attributed to Enchodus (Fig. a), Pachyrhizodus leptopsis Cope, 1874 (Fig. d), Anomoedus (Fig. e), and the garfish Lepisosteus and/or ?Atractosteus (Figs. b,h).
The selachian assemblage is diverse (30+ species) including previously undescribed taxa, and rather different than others from the North American Late Cretaceous. It has been interpreted as near-beach with a large number of small Scapanorhynchus teeth (over 50%) and low number of anacoracids (2%). Sclerorhynchoid batoids (23%) are predominated by Ptychotrygon and the rhinobatoids (16%) by Pseudohypolophus. A large number of dermal elements were present but not assigned to particular taxa (Fig. ).

CHONDRICHTHYANS. (Click on image for Genus Page)

Abbrev.: WLP1989 = Williamson, Lucas & Pence (1989); W&F1993 = Welton & Farish (1993); C&C1999 = Cappetta & Case (1999
HYBODONTIFORMES
	?Egertonodus sp. Larger size (1.5cm), less conical cusp, finer folds, more separated cusplets. Singular example not previously reported from North America.
	Meristodonoides cf. montanensis (CASE, 1978) Underwood & Cumbaa (2010) erected this genus. Variable shoulders & cusp ornamentation (striations), common in fauna. WLP1989:241 included as H. cf butleri.
	Planohybodus sp. Larger tooth, flatter cusp, higher shoulders, cusplets may be more numerous. Scarce in assemblage. Genus not previously reported from North America.
	Lonchidion sp. Possibly due to the small size, only one specimen has been recovered -- amazingly, the roots were preserved. Meyer (1974) included L. breve from the Santonian of TX and this specimen is similar.
PTYCHODONTIFORMES
	Ptychodus mortoni AGASSIZ 1839 More often recovered from deeper waters, these teeth are relatively scarce in the assemblage. WLP1989:241 reported this taxon.
? SQUATINFORMES
	? Parasquatina sp. Represented by very small teeth; uncommon. WLP1989:241 included Squatina sp. in the fauna, however the tooth-design was closer to Cederstroemia as included herein.
ORECTOLOBIFORMES
	Cantioscyllium aff. decipiens WOODWARD, 1889 Common in the fauna; WLP1989:241 included as C. decipiens.
	Chiloscyllium sp. Rare, known from a single specimen. Small (<1.5 mm) teeth with smooth crown and orectolobid root.
	Cederstroemia ziaensis BOURDON et al, 2011 5.0 - 7.0 mm teeth with thick, elongated apron; uncommon in the fauna. Included by Williamson et al (1989: fig 3f,g) as Squatina sp.
	Columbusia cf. fragilis CASE et al, 2001 Small, 2.0 mm class teeth with elongated, mesodistally compressed apron. Scarce.
LAMNIFORMES
ANACORACIDS
	Scindocorax novimexicanus BOURDON et al, 2011 Small (<6 mm class), thin cusp, cutting design. Relatively common.
	Scindocorax aff. novimexicanus BOURDON et al, 2011 Small (<5 mm class), thicker teeth of a tearing design, a less common variation?
	Squalicorax cf. S. lindstromi (DAVIS, 1890) Small homogeneus serrations, short distal shoulder and straight to convex lower mesial cutting edge. WLP1989:239 included as S. kaupi.
	Squalicorax aff. yangaensis (DARTEVILLE & CASIER, 1943) Tooth (convex lwr mesial edge, enlarged mesial serrations) corresponds with yangaensis (shoulder a bit longer). Reported by Wolberg (1989) as present in L. Cret NM.
"CRETOXYRHINIDS"
	Cretoxyrhina mantelli (AGASSIZ, 1843) Scarce tooth-design in this shallow water environment.
"EOPTOLAMNIDS"
	An undescribed eoptolamnid is present in the fauna and will be published at a later date.
"MITSUKURINIDS"
	Scapanorhynchus puercoensis BOURDON et al., 2011 Small (3-15 mm) and most common tooth-design in fauna; S.lewisi-like taxon; cusplets in A1-A2 positions (but larger).
	Scapanorhynchus ? puercoensis-like Much larger version of Scapanorhynchus puercoensis design.
	Scapanorhynchus cf tenuis (CASE et al, 2001) Small teeth but with different positional designs than S. puercensis.
	Scapanorhynchus cf texanus (ROEMER, 1849) Large teeth lack basal labial folds & narrower cusplets, otherwise texanus-like. WLP1989:239 report as S. raphiodon
"ODONTASPIDIDS"
	Carcharias sp Smooth crown, no basal labial folds, med-strong neck. Probably undescribed species but general condition not good enough to properly describe.
	Eostriatolamia sp Folded lower labial face, smooth lingual, wide neck. Similarites with Carcharias & Cenocarcharias but different from each - only 5 examples.
	Pueblocarcharias kawaikensis BOURDON et al, 2011 Smooth lingual face, complex basal folds on labial, multiple elongate cusplets; reminiscent of Palaeohypotodus, a Paleogene taxon
"OTODONTIDS"
	Cretalamna sp Known from several non-diagnostic examples. Appendiculata is a paleobucket, just go with genus.
SCLERORHYNCHIFORMES
"SCLERORHYNCHIDS"
	Ischyrhiza aff. I. mira LEIDY, 1856 These oral teeth are very cuspidate & small (2mm-class) - ?juvenile. Relatively common.
	Ischyrhiza aff. mira LEIDY, 1856 Rostral denticles I. cf mira in design. WLP1989:241 included as I. mira.
	Onchosaurus sp. Based on fragmentary rostral spine peduncles (including NMMNH P-4013 & 37421 to left), WLP1989:241 reported this genus in the fauna.
	? Onchosaurus Small, 3-4 mm-class undescribed tooth-design which appears to be batoid (not orectolobid per Siverson 2009). Cappetta (2010) agreed it could be Onchosaurus.
	Sclerorhynchus sp. Rostral denticle with incomplete posterior carina; lacking oral teeth, reluctant to attribute to S. atavus.
"PTYCHOTRYGONIDS"
	Ptychotrygon eutawensis CASE et al 2001 Dual transverse troughs, abundant. WLP1989:241 included triangularis in the fauna.
	? Ptychotrygon eutawensis CASE et al 2001 Most common small rostral denticle-design in the fauna. Likely from the most common ptychotrygonid. Cappetta (pers com 2009) disagrees -- not Ptychotrygon.
	Texatrygon stouti BOURDON et al, 2011 Crown generally lacks ornamentation & multiple transverse ridges; very stout crown with thick visor. 4mm class specimens. Cappetta (pers com 2009) agrees to genus not hooveri (lacks ridges).
	? Texatrygon stouti This additional rostral spine design, present in assemblage, is interpreted to be associated with Texatrygon.
RAJIFORMES
Suborder RHINOBATOIDEI
	"Rhinobatos" sp Tiny 1mm class teeth found by micro-screening only. Foolish to go beyond generic level.
	Protoplatyrhina cf renae CASE 1978 Most don't compare particularly well with original description but better with Case & Cappetta (1999 pl 11.3) example.
	"Pseudohypolophus" ellipsis (CASE et al 2001) Crown offset relative to nutrient groove differs from Thurmond's (1971) text. Tooth similar to C&C (1999: pl 28 & 29); not W&F (1993:134).
	? Myledaphus sp COPE 1876 Several examples that lack the crown ornamentation associated with M. bipartitus; but with the high roots of that genus.

AKNOWLEDGEMENTS