Bio

I have broad interests in paleobiology and Earth history. My current research projects include quantifying body-size bias in biodiversity databases and studying reef ecology across the Late Devonian extinctions.

Education & Certifications

  • B.A., University of California, Berkeley, Geology and Integrative Biology (2023)

Contact

  • Academic
    lxkahn@stanford.edu
    University - Student Department: Earth & Planetary Sciences Position: Graduate

Additional Info

All Publications

  • A 10-million-year biogeographic holding pen primed the Great American Biotic Interchange. Science (New York, N.Y.) Tseng, Z. J., Kahn, L. X., Pacheco-Castro, A., Carranza-Castañeda, O., Aranda-Gomez, J. J., Wang, Y., Chávez-Ambriz, J. C., Hannold, C., McDonald, H. G., Wang, X. 2026; 393 (6810): 532-536

    Abstract

    The movement of taxa between North and South America across the Panamanian land bridge, known as the Great American Biotic Interchange (GABI), established modern-day mammal assemblages in the Americas, heralding the decisive end of what has been called the "splendid isolation" of the South American fauna. Lacking substantive low-latitude records, previous work on this pattern relied on South American and temperate North American fossils to conclude that pulsed interchanges began about 2.8 million years ago (mya). Based on new low-latitude fossil data from México, we found evidence for a prolonged, triphasic interchange. Phase 1 consisted of the initial accumulation of northern higher-latitude mammals in a Mexican "holding pen" beginning 10 mya. Dispersal began in phase 2, with a strong north-south gradient and increasing biogeographic connections (7 to 3 mya). The final phase consisted of the already well-described taxonomic pulses (from ~2.8 mya).

    View details for DOI 10.1126/science.aef2893

    View details for PubMedID 42531382

  • THE STRATIGRAPHIC RECORD OF THE ARRIVAL OF THE SACRAMENTO AND SAN JOAQUIN RIVERS TO THE CALIFORNIA COAST, USA JOURNAL OF SEDIMENTARY RESEARCH Kahn, L. X., Zhang, Y., Finnegan, S., Hodgin, E. B., Swanson-hysell, N. L. 2025; 95 (5): 946-958

    View details for DOI 10.2110/jsr.2024.153

    View details for Web of Science ID 001668972300001

  • An 800-year record of benthic foraminifer images and 2D morphometrics from the Santa Barbara Basin SCIENTIFIC DATA Kahanamoku-Meyer, S. S., Samuels-Fair, M., Kamel, S. M., Stewart, D., Wu, B., Kahn, L. X., Titcomb, M., Mei, Y., Bridge, R., Li, Y., Sinco, C., Moreno, J., Epino, J. T., Gonzalez-Marin, G., Latt, C., Fergus, H., Duijnstee, I. A. P., Finnegan, S. 2024; 11 (1): 144

    Abstract

    The Santa Barbara Basin is an extraordinary archive of environmental and ecological change, where varved sediments preserve microfossils that provide an annual to decadal record of the dynamics of surrounding ecosystems. Of the microfossils preserved in these sediments, benthic foraminifera are the most abundant seafloor-dwelling organisms. While they have been extensively utilized for geochemical and paleoceanographic work, studies of their morphology are lacking. Here we use a high-throughput imaging method (AutoMorph) designed to extract 2D data from photographic images of fossils to produce a large image and 2D shape dataset of recent benthic foraminifera from two core records sampled from the center of the Santa Barbara Basin that span an ~800-year-long interval during the Common Era (1249-2008 CE). Information on more than 36,000 objects is included, of which more than 22,000 are complete or partially-damaged benthic foraminifera. The dataset also includes other biogenic microfossils including ostracods, pteropods, diatoms, radiolarians, fish teeth, and shark dermal denticles. We describe our sample preparation, imaging, and identification techniques, and outline potential data uses.

    View details for DOI 10.1038/s41597-024-02934-9

    View details for Web of Science ID 001154799000001

    View details for PubMedID 38291058

    View details for PubMedCentralID PMC10828449

https://orcid.org/0009-0004-2301-5552