I am responsible for carrying out work related to the overall management and long-term preservation of the geoscience collection belonging to the Doerr School of Sustainability.

Current Role at Stanford

Assistant Collections Manager for the Geoscience Specimen Collection

Education & Certifications

  • PhD, Uppsala University, Evolutionary Organismal Biology (2016)
  • MSc, Michigan State University, Geological Sciences (2007)
  • BA, Macalester College, Geology (2004)

Work Experience

  • Study Abroad Instructor (Iceland), Michigan State University

    Study abroad course on the Natural History of Iceland.
    Participated September 2017, September 2018, March 2019, February 2023 and February 2024


    East Lansing, Michigan

  • Museum Assistant, Museum of Evolution, Uppsala University

    Department of Zoology, vertebrate wet-preserved collection. Jan-Sept 2021; Oct 2023-Jan 2024


    Uppsala, Sweden

  • Senior Assistant, Swedish Museum of Natural History

    Department of Environmental Research and Monitoring, Environmental specimen bank; September 2021-October 2022
    Department of Zoology, Entomology collection; October 2022-August 2023


    Stockholm, Sweden

  • Postdoctoral Researcher, Uppsala University

    Department of Evolutionary Organismal Biology, October 2018-November 2020


    Uppsala, Sweden

  • Postdoctoral Researcher, Imperial College London

    Department of Life Sciences, Silwood Park Campus; May 2014-June 2018


    Berkshire, England

  • Museum Assistant, Michigan State University Museum

    Zoology and Paleontology Collections, 2006-2007


    East Lansing, Michigan

  • Intern, American Museum of Natural History

    Department of Paleontology, Fossil Mammal Type Rehousing Project, summer 2006


    New York, New York

All Publications

  • A well-preserved 'placoderm' (stem-group Gnathostomata) upper jaw from the Early Devonian of Mongolia clarifies jaw evolution. Royal Society open science Brazeau, M. D., Yuan, H., Giles, S., Jerve, A. L., Zorig, E., Ariunchimeg, Y., Sansom, R. S., Atwood, R. C. 2023; 10 (2): 221452


    The origin of jaws and teeth remains contentious in vertebrate evolution. 'Placoderms' (Silurian-Devonian armoured jawed fishes) are central to debates on the origins of these anatomical structures. 'Acanthothoracids' are generally considered the most primitive 'placoderms'. However, they are so far known mainly from disarticulated skeletal elements that are typically incomplete. The structure of the jaws-particularly the jaw hinge-is poorly known, leaving open questions about their jaw function and comparison with other placoderms and modern gnathostomes. Here we describe a near-complete 'acanthothoracid' upper jaw, allowing us to reconstruct the likely orientation and angle of the bite and compare its morphology with that of other known 'placoderm' groups. We clarify that the bite position is located on the upper jaw cartilage rather than on the dermal cheek and thus show that there is a highly conserved bite morphology among most groups of 'placoderms', regardless of their overall cranial geometry. Incorporation of the dermal skeleton appears to provide a sound biomechanical basis for jaw origins. It appears that 'acanthothoracid' dentitions were fundamentally similar in location to that of arthrodire 'placoderms', rather than resembling bony fishes. Irrespective of current phylogenetic uncertainty, the new data here resolve the likely general condition for 'placoderms' as a whole, and as such, ancestral morphology of known jawed vertebrates.

    View details for DOI 10.1098/rsos.221452

    View details for PubMedID 36844806

    View details for PubMedCentralID PMC9943883

  • Endocranial morphology of the petalichthyid placoderm <i>Ellopetalichthys</i> <i>scheii</i> from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms CANADIAN JOURNAL OF EARTH SCIENCES Castiello, M., Jerve, A., Burton, M., Friedman, M., Brazeau, M. D. 2021; 58 (1): 93-104
  • Endochondral bone in an Early Devonian 'placoderm' from Mongolia. Nature ecology & evolution Brazeau, M. D., Giles, S., Dearden, R. P., Jerve, A., Ariunchimeg, Y., Zorig, E., Sansom, R., Guillerme, T., Castiello, M. 2020; 4 (11): 1477-1484


    Endochondral bone is the main internal skeletal tissue of nearly all osteichthyans-the group comprising more than 60,000 living species of bony fishes and tetrapods. Chondrichthyans (sharks and their kin) are the living sister group of osteichthyans and have primarily cartilaginous endoskeletons, long considered the ancestral condition for all jawed vertebrates (gnathostomes). The absence of bone in modern jawless fishes and the absence of endochondral ossification in early fossil gnathostomes appear to lend support to this conclusion. Here we report the discovery of extensive endochondral bone in Minjinia turgenensis, a new genus and species of 'placoderm'-like fish from the Early Devonian (Pragian) of western Mongolia described using X-ray computed microtomography. The fossil consists of a partial skull roof and braincase with anatomical details providing strong evidence of placement in the gnathostome stem group. However, its endochondral space is filled with an extensive network of fine trabeculae resembling the endochondral bone of osteichthyans. Phylogenetic analyses place this new taxon as a proximate sister group of the gnathostome crown. These results provide direct support for theories of generalized bone loss in chondrichthyans. Furthermore, they revive theories of a phylogenetically deeper origin of endochondral bone and its absence in chondrichthyans as a secondary condition.

    View details for DOI 10.1038/s41559-020-01290-2

    View details for PubMedID 32895518

  • Vascularization and odontode structure of a dorsal ridge spine of Romundina stellina Ørvig 1975. PloS one Jerve, A., Qu, Q., Sanchez, S., Ahlberg, P. E., Haitina, T. 2017; 12 (12): e0189833


    There are two types of dermal skeletons in jawed vertebrates: placoderms and osteichthyans carry large bony plates (macromery), whereas chondrichthyans and acanthodians are covered by small scales (micromery). Fin spines are one of the last large dermal structures found on micromeric taxa and offer a potential source of histology and morphology that can be compared to those found on macromeric groups. Dermal fin spines offer a variety of morphology but aspects of their growth modes and homology are unclear. Here, we provide detailed descriptions of the microstructure and growth of a dorsal ridge spine from the acanthothoracid placoderm, Romundina stellina, using virtual three-dimensional paleohistological datasets. From these data we identify several layers of dentine ornamentation covering the lateral surfaces of the spine and reconstructed their growth pattern. We show that this spine likely grew posteriorly and proximally from a narrow portion of bone located along the leading edge of the spine. The spine is similarly constructed to the scales with a few exceptions, including the absence of polarized fibers distributed throughout the bone and the presence of a thin layer of perichondral bone. The composition of the spine (semidentine odontodes, dermal bone, perichondral bone) is identical to that of the Romundina dermal plates. These results illustrate the similarities and differences between the dermal tissues in Romundina and indicate that the spine grew differently from the dentinous fin spines from extant and fossil chondrichthyans. The morphology and histology of Romundina is most similar to the fin spine of the probable stem osteichthyan Lophosteus, with a well-developed inner cellular bony base and star-shaped odontodes on the surface. Results from these studies will undoubtedly have impact on our understanding of fossil fin spine histology and evolution, contributing to the on-going revision of early gnathostome phylogeny.

    View details for DOI 10.1371/journal.pone.0189833

    View details for PubMedID 29281687

    View details for PubMedCentralID PMC5744956

  • A three-dimensional placoderm (stem-group gnathostome) pharyngeal skeleton and its implications for primitive gnathostome pharyngeal architecture JOURNAL OF MORPHOLOGY Brazeau, M. D., Friedman, M., Jerve, A., Atwood, R. C. 2017; 278 (9): 1220-1228


    The pharyngeal skeleton is a key vertebrate anatomical system in debates on the origin of jaws and gnathostome (jawed vertebrate) feeding. Furthermore, it offers considerable potential as a source of phylogenetic data. Well-preserved examples of pharyngeal skeletons from stem-group gnathostomes remain poorly known. Here, we describe an articulated, nearly complete pharyngeal skeleton in an Early Devonian placoderm fish, Paraplesiobatis heinrichsi Broili, from Hunsrück Slate of Germany. Using synchrotron light tomography, we resolve and reconstruct the three-dimensional gill arch architecture of Paraplesiobatis and compare it with other gnathostomes. The preserved pharyngeal skeleton comprises elements of the hyoid arch (probable ceratohyal) and a series of branchial arches. Limited resolution in the tomography scan causes some uncertainty in interpreting the exact number of arches preserved. However, at least four branchial arches are present. The final and penultimate arches are connected as in osteichthyans. A single median basihyal is present as in chondrichthyans. No dorsal (epibranchial or pharyngobranchial) elements are observed. The structure of the pharyngeal skeleton of Paraplesiobatis agrees well with Pseudopetalichthys from the same deposit, allowing an alternative interpretation of the latter taxon. The phylogenetic significance of Paraplesiobatis is considered. A median basihyal is likely an ancestral gnathostome character, probably with some connection to both the hyoid and the first branchial arch pair. Unpaired basibranchial bones may be independently derived in chondrichthyans and osteichthyans.

    View details for DOI 10.1002/jmor.20706

    View details for Web of Science ID 000407687900005

    View details for PubMedID 28543631

    View details for PubMedCentralID PMC5575467

  • Morphology and histology of acanthodian fin spines from the late Silurian Ramsasa E locality, Skane, Sweden PALAEONTOLOGIA ELECTRONICA Jerve, A., Bremer, O., Sanchez, S., Ahlberg, P. E. 2017; 20 (3)

    View details for DOI 10.26879/749

    View details for Web of Science ID 000419760900004

  • Three-dimensional paleohistology of the scale and median fin spine of Lophosteus superbus (Pander 1856). PeerJ Jerve, A., Qu, Q., Sanchez, S., Blom, H., Ahlberg, P. E. 2016; 4: e2521


    Lophosteus superbus is one of only a handful of probable stem-group osteichthyans known from the fossil record. First collected and described in the late 19th century from the upper Silurian Saaremaa Cliff locality in Estonia, it is known from a wealth of disarticulated scales, fin spines, and bone fragments. In this study we provide the first description of the morphology and paleohistology of a fin spine and scale from Lophosteus using virtual thin sections and 3D reconstructions that were segmented using phase-contrast synchrotron X-ray microtomography. These data reveal that both structures have fully or partially buried odontodes, which retain fine morphological details in older generations, including sharp nodes and serrated ridgelets. The vascular architecture of the fin spine tip, which is composed of several layers of longitudinally directed bone vascular canals, is much more complex compared to the bulbous horizontal canals within the scale, but they both have distinctive networks of ascending canals within each individual odontode. Other histological characteristics that can be observed from the data are cell spaces and Sharpey's fibers that, when combined with the vascularization, could help to provide insights into the growth of the structure. The 3D data of the scales from Lophosteus superbus is similar to comparable data from other fossil osteichthyans, and the morphology of the reconstructed buried odontodes from this species is identical to scale material of Lophosteus ohesaarensis, casting doubt on the validity of that species. The 3D data presented in this paper is the first for fossil fin spines and so comparable data is not yet available. However, the overall morphology and histology seems to be similar to the structure of placoderm dermal plates. The 3D datasets presented here provide show that microtomography is a powerful tool for investigating the three-dimensional microstructure of fossils, which is difficult to study using traditional histological methods. These results also increase the utility of fin spines and scales suggest that these data are a potentially rich source of morphological data that could be used for studying questions relating to early vertebrate growth and evolution.

    View details for DOI 10.7717/peerj.2521

    View details for PubMedID 27833794

    View details for PubMedCentralID PMC5101592

  • Embryonic development of fin spines in Callorhinchus milii (Holocephali); implications for chondrichthyan fin spine evolution. Evolution & development Jerve, A., Johanson, Z., Ahlberg, P., Boisvert, C. 2014; 16 (6): 339-53


    Fin spines are commonly known from fossil gnathostomes (jawed vertebrates) and are usually associated with paired and unpaired fins. They are less common among extant gnathostomes, being restricted to the median fins of certain chondrichthyans (cartilaginous fish), including chimaerids (elephant sharks) and neoselachians (sharks, skates, and rays). Fin spine growth is of great interest and relevance but few studies have considered their evolution and development. We investigated the development of the fin spine of the chimaerid Callorhinchus milii using stained histological sections from a series of larval, hatchling, and adult individuals. The lamellar trunk dentine of the Callorhinchus spine first condenses within the mesenchyme, rather than at the contact surface between mesenchyme and epithelium, in a manner more comparable to dermal bone formation than to normal odontode development. Trabecular dentine forms a small component of the spine under the keel; it is covered externally with a thin layer of lamellar trunk dentine, which is difficult to distinguish in sectioned adult spines. We suggest that the distinctive characteristics of the trunk dentine may reflect an origin through co-option of developmental processes involved in dermal bone formation. Comparison with extant Squalus and a range of fossil chondrichthyans shows that Callorhinchus is more representative than Squalus of generalized chondrichthyan fin-spine architecture, highlighting its value as a developmental model organism.

    View details for DOI 10.1111/ede.12104

    View details for PubMedID 25378057