There are many diseases associated with hard tissue, such as osteoporosis, osteoarthritis and periodontal disease, and their patients have increased with the advent of an aging society. In this laboratory, for the treatment of these diseases, we are developing regenerative research on hard tissue (bone, cartilage, teeth) by setting three keyword; growth factors, extracellular microenvironment and stem cell.

Through field-based surveys, I am conducting research to clarify the geology and paleoenvironment of Mesozoic strata distributed in the Hokuriku region. I am also conducting research to clarify ecology of dinosaurs, such as their gait, walking speed, and gregarious behavior, based on dinosaur footprints. We will also be researching effective methods for museum exhibitions that focus on dinosaur fossils.

I am actively involved in paleontological excavations spanning Mongolia, Kenya, and northern Okayama Prefecture, while simultaneously conducting meticulous paleoenvironmental reconstructions based on robust geological investigations. Moreover, my endeavors extend to the comprehensive reconstruction of the entire ecological framework of the relevant time periods, encompassing small vertebrates, insects, and invertebrates, achieved through the discernment of the intricate interconnections between fossils and their corresponding stratigraphic contexts. Furthermore, our team enthusiastically engages in lifelong learning endeavors, exemplified by organizing exhibitions, workshops, and lectures that showcase esteemed fossil specimens.

In Japan, fossils of small mammals, such as those the size of mice or moles, are rarely found in older geological strata. This scarcity is largely due to the fact that fossil searches for small mammals have primarily focused on sediments accumulated in limestone fissures or caves, which are uncommon in strata older than 800,000 years. As a result, discoveries of small mammals from these earlier periods have been limited. Using new methods, I have successfully extracted small mammal fossils from strata dating back 3.5 million and 26 million years. My work contributes new insights into Japan’s fossil mammal record, which has traditionally been dominated by reports of large mammals such as elephants and deer, and aims to shed light on transitions in mammalian fauna across East Asia.

Bone histology is the study of bone function and growth by sectioning bones into thin slices to visualize internal tissues. This technique has proven instrumental in uncovering the physiology and ecology of extinct animals, providing insights into their growth rate, age, metabolism, and degree of aquatic adaptation — factors that were previously challenging to reconstruct. My research focuses on employing bone histology to explore the life and adaptive processes of large vertebrates, such as dinosaurs and mammals. Specifically, I aim to uncover what factors influenced these creatures to evolve into giants or diminutive forms and how terrestrial vertebrates altered their physiology and bone structure to successfully readapt to aquatic environments.

Animal bones typically contain growth marks, similar to those of tree rings. Previous studies have utilized these marks to reconstruct the growth of extinct animals, especially dinosaurs, and further investigate their physiology and ecology. Using specimens and data that I have collected through fieldwork and museum visits all over the world, I hope to contribute to our understanding of the link between life histories of fossil animals and macroevolutionary patterns.

Fieldworks in and out of Japan and describing dinosaur fossils. Mainly working on hadrosaurids, plant-eating dinosaurs that thrived during the late Cretaceous. Also reconstructing dinosaur soft-tissue anatomy through osteological and non-osteological fossils.

Fieldworks:
Mongolia, USA, Canada

Named species:
Kamuysaurus japonicus, Yamatosaurus izanagii, Paralitherizinosaurus japonicus, Ravjaa ishiii