LSA ASSOCIATES, INC. FRESNO RIVERSIDE 20 EXECUTIVE PARK, SUITE 200 949.553.0666 TEL BERKELEY PALM SPRINGS ROCKLIN IRVINE, CALIFORNIA 92614 949.553.8076 FAX CARLSBAD PT. RICHMOND SAN LUIS OBISPO

MEMORANDUM

DATE: January 17, 2017

TO: Matt Collings, Assistant General Manager, Moulton Niguel Water District

FROM: Sarah Rieboldt, Ph.D.

SUBJECT: Paleontological Analysis of the Moulton Niguel Water District Operations Center and Site Consolidation Project, City of Laguna Hills, County of Orange, California

INTRODUCTION The Moulton Niguel Water District (MNWD) proposes the MNWD Operations Center and Site Consolidation Project (project) in the City of Laguna Hills (City), County of Orange, California. The MNWD is currently operating within an infrastructure that combines approximately 40,000 square feet (sf) of buildings with over 100 employees on two separate, noncontiguous sites. In addition, most of the existing buildings on the project site are overcapacity and becoming increasingly inefficient and maintenance intensive. Therefore, this project seeks to consolidate and update the MNWD administrative offices and associated buildings within the project site.

This memorandum was prepared to ensure project compliance with all applicable State and City regulations and requirements regarding paleontological resources, including the California Environmental Quality Act (CEQA): Public Resources Code (PRC) Division 13, Chapter 2.6; the State CEQA Guidelines: California Code of Regulations, Title 14, Chapter 3, Appendix G; PRC 5097.5; the General Plan for the City (City of Laguna Hills, 2009); and the Society of Vertebrate Paleontology (SVP, 2010). This memorandum addresses the potential for the project to impact paleontological resources and, if needed, includes mitigation measures and other recommendations to minimize these impacts. The MNWD is the Lead Agency under CEQA.

PROJECT DESCRIPTION AND LOCATION In order to accommodate the administrate offices on the project site, MNWD proposes to construct a two-story office building of approximately 45,000 sf to serve as the MNWD Operations Center. The project will also include two new one-story buildings: (1) a 12,500 sf building that will contain various shop uses, lockers, restrooms, and standby facilities; and (2) a 4,800 sf building that will contain fleet uses including service bays, parts, storage, and an emergency generator. Two of the existing buildings on the site totaling approximately 21,735 sf will be refurbished and used primarily for warehouse and storage. The remaining four buildings currently on site will be demolished and removed from the site. The project will also expand and relocate an existing fuel island and relocate various material bins and outdoor storage areas for MNWD supplies. The project will also involve construction of new parking areas and access roads; construction of a retaining wall along the north side of the property; excavation of a retention basin in the northwest corner of the project site; and installation of new wet and dry utilities, fire hydrants, landscaping, fencing, signage, and lighting.

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The project site is generally located northeast of Moulton Parkway and bordered by Sunnyglen Avenue to the west, Imperial Drive to the south, and residential areas to the north and east. It is depicted on the United States Geological Survey (USGS) San Juan Capistrano, California 7.5-minute topographic quadrangle map in Township 7 South, Range 8 West, Section 10, San Bernardino Baseline and Meridian (USGS, 1981; Figure 1).

METHODS LSA Associates, Inc. (LSA) examined geologic maps of the project site and reviewed relevant geological and paleontological literature to determine which geologic units are present within the project site and whether fossils have been recovered within the project site or from those or similar geologic units elsewhere in the region. A search for known fossil localities was also conducted through the Natural History Museum of Los Angeles County (LACM) in order to determine the status and extent of previously recorded paleontological resources within and surrounding the project site. On June 15, 2016, LSA Associate Ivan Strudwick conducted a reconnaissance pedestrian survey of the project site by walking random, nonlinear transects in areas where the ground surface was visible. Built areas (e.g., paved parking lots and areas containing buildings) were not surveyed.

RESULTS Literature Review The project is located at the northern end of the Peninsular Ranges Geomorphic Province, a 900-mile (mi) long northwest-southeast-trending structural block that extends from the Transverse Ranges in the north to the tip of Baja California in the south and includes the Los Angeles Basin (California Geological Survey, 2002; Norris and Webb, 1976). This province is characterized by mountains and valleys that trend in a northwest-southeast direction, roughly parallel to the San Andreas Fault. The total width of the province is approximately 225 mi, extending from the Colorado Desert in the east, across the continental shelf, to the Southern Channel Islands (i.e., Santa Barbara, San Nicolas, Santa Catalina, and San Clemente) (Sharp, 1976). It contains extensive pre- (more than 145 million years ago [Ma]) and Cretaceous (145 to 66 Ma) igneous and metamorphic rock covered by limited exposures of post-Cretaceous (less than 66 Ma) sedimentary deposits (Norris and Webb, 1976).

Geologic mapping by Morton and Miller (2006) shows that the project site contains Holocene to late in age (less than 126,000 years ago) Young Axial Channel Deposits and the early Pliocene to siltstone facies of the Capistrano Formation (Figure 2). In addition, the geotechnical report prepared for this project indicates the site is underlain by varying amounts of Artificial Fill placed during earlier development and backfilling of the two retention basins (Petra Geosciences, Inc., 2016).

Artificial Fill. Artificial Fill consists of sediments that have been removed from one location and transported to another location by human activity rather than by natural means. The transportation distance can vary from a few feet to many miles, and composition is dependent on the source and purpose. Artificial Fill was encountered throughout the project site from the surface to depths of 2 feet (ft) to 26 ft in borings and test pits conducted for the geotechnical investigation for this project

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LEGEND FIGURE 1 Project Location

Moulton Niguel Water District (MNWD) 0 1000 2000 Operations Center and Site Consolidation Project FEET Project Location and Vicinity SOURCE: USGS 7.5' Quad - San Juan Capistrano (1981), CA I:\MNW1501\GIS\ProjectLocation_USGS.mxd (7/13/2016) LEGEND FIGUR E 2 Project Area

!Ge!olog ic Unit ! ! ! !! !!! !! ! ! !!! ! ! ! ! Qy a – Young Axial Ch annel Deposits Tn - Nig uel Form ation Moulton Niguel Water District (MNWD) Tcs – Capistrano Form ation, siltstone facies 0 100 200 Operations Center and Site Consolidation Project FEET Tm - Monterey Form ation Geolog y Map SOUR CE: Bing Maps (2014); Morton and Miller (2006) I:\MNW1501\GIS\Geolog y .m xd (7/13/2016) LSA ASSOCIATES, INC.

(Petra Geosciences, Inc., 2016). The deepest fill area encountered was in the vicinity of the western retention basin.

While Artificial Fill may contain fossils, these fossils have been removed from their original location and are thus out of stratigraphic context. Therefore, they are not considered important for scientific study. As such, Artificial Fill has no paleontological sensitivity.

Young Axial Channel Deposits. The Young Axial Channel Deposits are Holocene to late Pleistocene in age (less than 126,000 years ago) and consist of slightly to moderately consolidated silt, sand, and gravel (Morton and Miller, 2006). They formed as streams and washes carried sediment down from higher elevations in the surrounding hills.

Although Holocene deposits can contain remains of plants and , generally not enough time has passed for the remains to become fossilized. In addition, the remains are conspecific with modern species, and these remains are usually not considered to be scientifically important. However, the older Pleistocene deposits that may be reached below a depth of approximately 10 ft have produced scientifically important fossils elsewhere in the County of Orange and the region (Jefferson, 1991a, 1991b; Miller, 1971; Reynolds and Reynolds, 1991; Springer et al., 2009). These older deposits span the end of the Rancholabrean North American Land Age (NALMA), which was named for the Rancho La Brea fossil site in central Los Angeles and dates from 240,000 to 11,000 years ago (Alroy, 2000). The presence of Bison defines the beginning of the Rancholabrean NALMA (Bell et al., 2004), but fossils from this time also include other large and small , reptiles, fish, invertebrates, and plants. There is a potential to find these types of fossils in the older sediments of this geologic unit, which may be encountered below a depth of approximately 10 ft. Therefore, these deposits are assigned a low paleontological sensitivity above a depth of 10 ft and a high sensitivity below that mark.

Capistrano Formation, Siltstone Facies. The marine Capistrano Formation was deposited during the early Pliocene to late Miocene (3.6–11.62 Ma) (Eisentraut and Cooper, 2002). In this area, the formation has been divided into one named member (Oso Member) and one informal unit (siltstone facies) (Morton and Miller, 2006). The Oso Member formed in a shallow marine embayment; it is composed of white to light gray, massive, medium- to coarse-grained, weakly cemented sandstone with occasional matrix-supported pebbles and cobbles (Eisentraut and Cooper, 2002; Morton and Miller, 2006). In contrast, the siltstone facies accumulated in deep shelf and slope environments and consists of white to pale gray, massive to poorly bedded, friable siltstone and mudstone with rare tuffaceous and diatomaceous beds (Eisentraut and Cooper, 2002; Morton and Miller, 2006). The siltstone facies is mapped around the edges of the project site.

This formation has produced abundant and diverse scientifically significant fossils, many of which come from the siltstone facies. These fossils include bony fish, sharks, whales, porpoises, sea lions, sea cows, and marine birds (Barnes and Raschke, 1991; Démeré and Berta, 2005; Ebeling, 1962; Eisentraut and Cooper, 2002; Smith, 2011). As such, these deposits are considered to have high paleontological sensitivity.

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Fossil Locality Search According to the locality search conducted by the LACM, there are no known fossil localities within the boundaries of the project. The LACM reports that the project site is underlain by deposits of younger Quaternary alluvium (i.e., Young Axial Channel Deposits) and the marine siltstone facies of the Capistrano Formation. The museum has many records of vertebrate localities from the Capistrano Formation in this area of Orange County. Two of the closest localities are LACM 4525, which lies directly east of the project just west of La Paz Road, and LACM 5472, which is northeast of the project. These localities produced specimens of undetermined invertebrates, sharks and rays (Chondrichthyes), and bony fish (Osteichthyes). Northwest of the project in the hills south and east of Aliso Creek, the museum has a series of localities from this formation. These localities, LACM 3183, 7057, and 65119 – 65123 produced a suit of marine vertebrates, including chimaera (Chimaera), eagle ray (Myliobatis), dusky shark (Carcharhinus), sixgill shark (Hexanchus), tiger shark (Galeocerdo), blue shark (Prionace), hammerhead shark (Sphyrna zygaena), basking shark (Cetorhinus), giant white shark (Carcharocles ), white sharks (Carcharodon and C. sulcidens), bonito sharks ( benedeni, I. hastalis, and I. oxyrinchus), angel shark (Squatina), wolf eel (Anarrhichthys), snake mackerel (Thrysocles), sailfish (Istiophoridae), wrasse (Pimelometopon), sheephead (Semicossyphus), halibut (Paralichthys), saber-toothed salmon (Smilodonichthys), turtle (Testudinata), crocodile (Crocodylidae), auklet (Cerorhinca), puffin (Mancalla diegensis), flamingo (Megapaloelodus opsigonus), sandpiper (Scolopacidae), loon (Gavia), booby (Morus), grebe (Podicipedidae), shearwater (Puffinus), sea lion (Imagotaria), four- legged marine mammal (Desmostylus), sea cow (Dugongidae), porpoise (Piscolithax), (Scaldicetus), (Ziphiidae), dolphin (Delphinoidea), primitive (), and rorqual whale (Balaenopteridae).

The LACM believes that shallow excavations in the younger Quaternary alluvial deposits in the project site are unlikely to recover any scientifically important vertebrate fossils. However, excavations into the Capistrano Formation beneath the alluvial deposits in the central portion of the project site or where it is exposed around the periphery may encounter scientifically significant vertebrate remains and should be monitored to recover those remains. A copy of the letter describing the locality search results from the LACM is provided in Attachment A.

Field Survey The entire project site exhibits major disturbance and has been highly altered from its original state. Two unused and now dry artificial water features (ponds) are located on the western portion of the project site, while the eastern portion contains a parking lot; several buildings; and piles of sand, gravel, and rock. A graded dirt road has been built around the periphery of the two settling ponds. Brush covers 20–70 percent of the surface of the dry settling ponds, and ornamental vegetation is found over 10–50 percent of the western portion of the project site. Where the ground surface is visible in these areas, it consists of silt and clay. The only area with native rock is a narrow area along the fence line on the north side in the middle of the project site. This area contains exposures of light- colored siltstone consistent with the siltstone facies of the Capistrano Formation as mapped by Morton and Miller (2006). No paleontological resources were encountered during the survey.

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CONCLUSIONS AND RECOMMENDATIONS Although no scientifically significant paleontological resources were identified directly within the project site during the locality search or field survey, the results of the locality search and literature review indicate that the project site encompasses deposits with high paleontological sensitivity. These high sensitivity deposits include the Young Axial Channel Deposits below a depth of 10 ft and the siltstone facies of the Capistrano Formation.

According to the geotechnical report prepared for this project, in the areas where the buildings will be constructed, all the Artificial Fill and approximately the uppermost 4 ft of Young Axial Channel Deposits will need to be removed and replaced with properly compacted fill (Petra Geosciences, Inc., 2016a). Moreover, the supplemental geotechnical report prepared for this project (Petra Geosciences, Inc. 2016b) recommends stone columns extending through the Young Axial Channel Deposits down to the siltstone facies of the Capistrano Formation to support two of the new buildings. In areas where the Artificial Fill, Young Axial Channel Deposits, and/or siltstone facies of the Capistrano Formation contact each other, overexcavation of the Young Axial Channel Deposits or the siltstone facies of the Capistrano Formation to depths of between 5 ft and 15 ft may be required (Petra Geosciences, Inc., 2016a). In addition, the grading plans for the project indicate the retention basin in the northwest corner of the project site will require excavation to approximately 8 ft below the current ground surface in an area where the siltstone facies of the Capistrano Formation underlies Artificial Fill at a depth of approximately 5 ft (Petra Geosciences, Inc., 2016a). Based on these excavation parameters, excavation associated with this project is expected to reach paleontologically sensitive deposits, and there is a potential for the project to impact paleontological resources. Therefore, in order to mitigate potential impacts to scientifically significant nonrenewable paleontological resources, as required by CEQA Appendix G, PRC Section 5097.5, and the policies in the City’s General Plan (City of Laguna Hills, 2009), LSA recommends the following mitigation measure:

PALEO-1 Prior to commencement of any grading activity on site, the Moulton Niguel Water District Assistant General Manager, or designee, shall verify that a paleontologist, who is listed on the County of Orange list of certified paleontologists, has been retained to develop a Paleontological Resources Impact Mitigation Program (PRIMP) for this project. The PRIMP shall include the methods that will be used to protect paleontological resources that may exist within the project site, as well as procedures for monitoring, fossil preparation and identification, curation into a repository, and preparation of a report at the conclusion of grading. The PRIMP shall be consistent with the guidelines of the Society of Vertebrate Paleontology (SVP) and include, but not be limited to, the following:

 Excavation and grading activities in deposits with high paleontological sensitivity (Young Axial Channel Deposits beginning at a depth of 10 ft below the existing ground surface and the siltstone facies of the Capistrano Formation) shall be monitored by a paleontological monitor following a PRIMP. No monitoring is required for excavations in deposits with no or low paleontological sensitivity (Artificial Fill or the Young Axial Channel Deposits from the surface to a depth of 10 ft).  If paleontological resources are encountered during the course of ground disturbance, the paleontological monitor shall have the authority to temporarily

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redirect construction away from the area of the find in order to assess its significance.  Collected resources shall be prepared to the point of identification, identified to the lowest taxonomic level possible, cataloged, and curated into the permanent collections of a scientific institution.  At the conclusion of the monitoring program, a report of findings shall be prepared to document the results of the monitoring program.  In the event that paleontological resources are encountered when a paleontological monitor is not present, work in the immediate area of the find shall be redirected and a paleontologist should be contacted to assess the find for significance. If determined to be significant, the fossil shall be collected from the field.

REFERENCES Alroy, John 2000 New methods for quantifying macroevolutionary patterns and processes. Paleobiology 26(4):707–733.

Barnes, Lawrence G., and Rodney E. Raschke 1991 Gomphotaria pugnax, a New and Species of Late Miocene Dusignathine Otariid Pinniped (Mammalia: Carnivora) from California. Natural History Museum of Los Angeles County Contributions in Science 426:1–16.

Bell, Christopher J., Ernest L. Lundelius, Jr., Anthony D. Barnosky, Russell W. Graham, Everett H. Lindsay, Dennis R. Ruez, Jr., Holmes A. Semken, Jr., S. David Webb, and Richard J. Zakrzewski 2004 The Blancan, Irvingtonian, and Rancholabrean Mammal Ages. Chapter 7 in Michael O. Woodburne, ed., Late Cretaceous and Cenozoic Mammals of North America. pp. 232–314.

California Geological Survey 2002 California Geomorphic Provinces. California Geologic Survey Note 36. California Department of Conservation.

City of Laguna Hills 2009 Laguna Hills General Plan. Adopted July 14, 2009. Website: http://www.ci.laguna- hills.ca.us/174/Planning-Division, accessed July 2016.

Démeré, Thomas A., and Annalisa Berta 2005 New skeletal material of Thalassoleon (Otariidae: Pinnipedia) from the Late Miocene- Early Pliocene (Hemphillian) of California. Bulletin of the Florida Museum of Natural History 45(4):379–411.

Ebeling, Alfred W. 1962 Scopelogadus (?) capistranensis, a New Fossil Melamphaid (Pisces: Teleostei) from Capistrano Beach, California. Postilla, Yale Peabody Museum of Natural History 71:1–6.

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Eisentraut, P., and J. Cooper 2002 Development of a Model Curation Program for Orange County’s Archaeological and Paleontological Collections. Prepared by California State University, Fullerton and submitted to the County of Orange Public Facilities Resources Department/Orange County Harbors, Beaches, and Parks (PFRD/HBP).

Jefferson, George T. 1991a A Catalogue of Late Quaternary Vertebrates from California: Part One: Non-marine Lower Vertebrate and Avian Taxa. Natural History Museum of Los Angeles County Technical Reports No. 5, Los Angeles.

1991b A Catalogue of Late Quaternary Vertebrates from California: Part Two: Mammals. Natural History Museum of Los Angeles County Technical Reports No. 7, Los Angeles.

Miller, W.E. 1971 Pleistocene Vertebrates of the Los Angeles Basin and Vicinity (Exclusive of Rancho La Brea). Los Angeles County Museum of Natural History Bulletin, Science: No. 10.

Morton, Douglas M., and Fred K. Miller 2006 Geologic Map of the San Bernardino and Santa Ana 30-minute by 60-minute quadrangles, California. Digital preparation by Pamela M. Cosette and Kelly R. Bovard. Prepared by the United States Geological Survey (USGS) in cooperation with the California Geological Survey. USGS Open File Report 2007-1217. Map Scale 1:100,000.

Norris, R.M., and R.W. Webb 1976 Geology of California. New York: John Wiley and Sons, Inc. 379 pp.

Petra Geosciences, Inc. 2016a Geotechnical Investigation, Proposed Improvements at the Moulton Niguel Water District Operations Center, 26161 Gordon Road, Laguna Hills, California. Prepared for the Moulton Niguel Water District, January 25, 2016. Petra Geosciences, Inc. Project No. 15-458. 2016b Supplemental Geotechnical Investigation, Proposed Improvements at the Moulton Niguel Water District Operations Center, 26161 Gordon Road, Laguna Hills, California. Prepared for the Moulton Niguel Water District, December 14, 2016. Petra Geosciences, Inc. Project No. 15-458.

Reynolds, R.E., and R.L. Reynolds 1991 The Pleistocene Beneath our Feet: Near-surface Pleistocene Fossils in Inland Southern California Basins. In M.O. Woodburne, R.E. Reynolds, and D.P. Whistler, eds., Inland Southern California: The Last 70 Million Years, Redlands, San Bernardino County Museum Special Publication 38(3 and 4): 41–43.

Sharp, R.P. 1976 Geology: Field Guide to Southern California. Kendall/Hunt Publishing Company, Second Edition: 181.

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Smith, N. Adam 2011 Taxonomic Revision and Phylogenetic Analysis of the Flightless Mancallinae (Aves, Pan- Alcidae). ZooKeys 91:1–116.

Society of Vertebrate Paleontology (SVP) 2010 Standard Procedures for the Assessment and Mitigation of Adverse Impacts to Paleontological Resources. Society of Vertebrate Paleontology. Impact Mitigation Guidelines Revision Committee. 11 pp.

Springer, Kathleen, Eric Scott, J. Christopher Sagebiel, and Lyndon K. Murray 2009 The Diamond Valley Lake Local Fauna: Late Pleistocene Vertebrates from Inland Southern California. In L.B. Albright, III, ed. Papers in Geology, Vertebrate Paleontology, and Biostratigraphy in Honor of Michael O. Woodburne, Museum of Northern Arizona Bulletin 65, pp. 217–236.

United States Geological Survey (USGS) 1981 San Juan Capistrano, California 7.5-minute topographic quadrangle. Published 1968, photorevised 1981. United States Geological Survey, Denver, Colorado.

Attachment: A: Paleontological Locality Search Results from the Natural History Museum of Los Angeles County

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ATTACHMENT A

PALEONTOLOGICAL LOCALITY SEARCH RESULTS FROM THE NATURAL HISTORY MUSEUM OF LOS ANGELES COUNTY

P:\MNW1501\Paleo\MNWD Operations Center Paleo Memo.docx «01/17/17» Vertebrate Paleontology Section Telephone: (213) 763-3325 Fax: (213) 746-7431 e-mail: [email protected]

14 July 2016

LSA Associates, Inc. 20 Executive Park, Suite 200 Irvine, California 92614

Attn: Sarah Rieboldt, Ph.D., Paleontologist re: Paleontological Resources Records Check for the proposed Moulton Niguel Water District Project, LSA Project # MNW1501, in the City of Laguna Hills, Orange County, project area

Dear Sarah:

I have thoroughly searched our paleontology collection records for the locality and specimen data for the proposed Moulton Niguel Water District Project, LSA Project # MNW1501, in the City of Laguna Hills, Orange County, project area as outlined on the portion of the San Juan Capistrano USGS topographic quadrangle maps that you sent to me via e-mail on 7 July 2016. We do not have any vertebrate fossil localities that lie directly within the proposed project boundaries, but we do have localities nearby from the same sedimentary deposits that occur in the proposed project area.

In the lower lying central portion of the proposed project area there may have been thin surface deposits of younger Quaternary Alluvium, derived from the surrounding more elevated terrain. These surface deposits, at least disturbed and possibly no longer existing, typically do not contain significant vertebrate fossils in the uppermost layers. The surrounding more elevated terrain has exposures of the marine late Miocene siltstone facies of the Capistrano Formation. We have a great number of vertebrate fossil localities from the Capistrano Formation in this portion of Orange County, but our closest localities from this rock unit are LACM 4525, directly east of the proposed project area just west of La Paz Road, and LACM 5472, just east of north of the eastern portion of the proposed project area, that produced fossil specimens of undetermined invertebrates, Invertebrata, sharks and ray, Chondrichthyes, and bony fish, Osteichthyes. North of the western portion of the proposed project area, in the hills south and east of Aliso Creek, we have a series vertebrate fossil localities from the Capistrano Formation including LACM 3183, 7057, and 65119-65123. These localities produced an extensive suite of fossil marine vertebrates including chimaea, Chimaera, eagle ray, Myliobatis, dusky shark, Carcharhinus, blue shark, Prionace, tiger shark, Galeocerdo, blue shark, Prionace, hammerhead shark, Sphyrna zygaena, sixgill shark, Hexanchus, backing shark, Cetorhinus, giant white shark, Carcharocles megalodon, white sharks, Carcharodon carcharias and Carcharodon sulcidens, bonito sharks, Isurus benedeni, Isurus hastalis, and Isurus oxyrinchus, angel shark, Squatina, wolf-eel, Anarrhichthys, snake mackerel, Thyrsocles, sailfish, Istiophoridae, wrasse, Pimelometopon, sheephead, Semicossyphus, halibut, Paralichthys, sabre-toothed salmon, Smilodonichthys, turtle, Testudinata, crocodile, Crocodylidae, auklet, Cerorhinca, puffin, Mancalla diegensis, flamingo, Megapaloelodus opsigonus, sandpiper, Scolopacidae, loon, Gavia, booby, Morus, grebe, Podicipedidae, shearwater, Puffinus, sea lion, Imagotaria, four-legged marine mammal, Desmostylus, sea cow, Dugongidae, porpoise, Piscolithax, sperm whale, Scaldicetus, beaked whale, Ziphiidae, dolphin, Delphinoidea, primitive baleen whale, Cetotheriidae, and rorqual whale, Balaenopteridae. The sailfish, Istiophoridae, from locality LACM 65119, was figured in the scientific literature by H.L. Fierstine and S.P. Applegate in 1968 (Billfish Remains from Southern California with Remarks on the Importance of the Predentary Bone. Bulletin of the Southern California Academy of Sciences, 67(1):29-39). In 2011 N.A. Smith published on the puffin, Mancalla, from locality LACM 3183 (Taxonomic revision and phylogenetic analysis of the flightless Mancallinae (Aves, Pan-Alcidae). ZooKeys, 91:1-116).

Just outside the western boundaries of the proposed project area there are exposures of the marine late Miocene Monterey Formation, and this rock unit almost certainly underlies the Capistrano Formation exposures in the rest of the proposed project area. Our closest vertebrate fossil locality from the Monterey Formation is LACM 7952, adjacent to the western border of the proposed project area, that produced a fossil specimen of sea cow, Dugongidae. Immediately to the southwest of the proposed project area we have a cluster of three fossil localities from the Monterey Formation, LACM 4919, 5786, and 7953, that produced fossil specimens of snake mackerel, Thyrsocles kriegeri, herring, Ganolytes cameo, sculpin, Cottidae, sea lion, Otariidae, sea cow, Dugongidae, and sperm whale, Scalidicetus. The fossil sperm whale specimen from locality LACM 5786 was figured in the scientific literature by S.A. McLeod (1988. A Fossil Sperm Whale from Orange County, California. Memoirs of the Natural History Foundation of Orange County, 2:22-28). Directly south of the proposed project area just north of La Paz Road our Monterey Formation locality LACM 7136 produced fossil specimens of bonito sharks, Isurus hastalis and Isurus oxyrinchus, snake mackerel, Thyrsocles, bass, Percichthyidae, leatherback turtle, Psephophorus, auklet, Praemancalla, false-toothed bird, Osteodontornis orri, booby, Morus lompocanus, shearwater, Puffinus barnesi, sea lions, Imagotaria downsi and Pithanotaria, and dolphin, Delphinoidea. The birds from locality LACM 7136 were published in the scientific literature by H. Howard (1978. Late Miocene marine birds from Orange County, California. Contributions in Science, Natural History Museum of Los Angeles County, 290:1-26). Just northwest of the proposed project area our Monterey Formation locality LACM 3863 produced a fossil specimen of baleen whale, Herpetocetus. Shallow excavations in the uppermost layers of the younger Quaternary Alluvium or fill material in the central portion of the proposed project area probably will not uncover significant fossil vertebrate remains. Deeper excavations in those areas that extend down into older sedimentary deposits of the Capistrano Formation or the Monterey Formation, or any excavations in the Capistrano Formation exposures around the margins of the proposed project area, however, may well encounter significant vertebrate fossils. Any substantial excavations in the proposed project area, therefore, should be closely monitored to quickly and professionally collect any specimens without impeding development. Also, sediment samples should be collected and processed to determine the small fossil potential in the proposed project area. Any fossils recovered during mitigation should be deposited in an accredited and permanent scientific institution for the benefit of current and future generations.

This records search covers only the vertebrate paleontology records of the Natural History Museum of Los Angeles County. It is not intended to be a thorough paleontological survey of the proposed project area covering other institutional records, a literature survey, or any potential on-site survey.

Sincerely,

Samuel A. McLeod, Ph.D. Vertebrate Paleontology enclosure: invoice