Anatomical Correlates Associated with the Bracing System of Extant Anatomical Correlates Associated with the Bracing System of Extant Crocodilians: addressing the Locomotor Inadequacies of the Indian Gharial Crocodilians: addressing the Locomotor Inadequacies of the Indian Gharial Steven W. Salisbury1 and Eberhard Frey2 Steven W. Salisbury1 and Eberhard Frey2 1School of Life Sciences, The University of Queensland, Brisbane, QLD 4072, Australia 1School of Life Sciences, The University of Queensland, Brisbane, QLD 4072, Australia ([email protected]); 2Staatliches Museum für Naturkunde Karlsruhe, Erbprinzenstrasse 13, ([email protected]); 2Staatliches Museum für Naturkunde Karlsruhe, Erbprinzenstrasse 13, D-76133 Karlsruhe, Germany ([email protected]) D-76133 Karlsruhe, Germany ([email protected]) All extant crocodilians brace their bodies against mechanical loading and during movement in a similar manner. This All extant crocodilians brace their bodies against mechanical loading and during movement in a similar manner. This type of bracing mechanism is referred to as the ‘eusuchian-type bracing system’. Differences in the configuration of type of bracing mechanism is referred to as the ‘eusuchian-type bracing system’. Differences in the configuration of the paravertebral shield and the length of the lateral epaxial muscles in the cranial half of the tail between Gavialis the paravertebral shield and the length of the lateral epaxial muscles in the cranial half of the tail between Gavialis gangeticus and other extant crocodilians correlate with the former’s apparent inability to high-walk at large sizes (> gangeticus and other extant crocodilians correlate with the former’s apparent inability to high-walk at large sizes (> approx. 50 kg). These characteristics probably also preclude any capacity for galloping. A further correlation exists approx. 50 kg). These characteristics probably also preclude any capacity for galloping. A further correlation exists between: the configuration of the dorsal cervical muscles; the equivalence in height of the neural arches on the between: the configuration of the dorsal cervical muscles; the equivalence in height of the neural arches on the vertebrae in the trunk; tail base and caudal-most portion of the neck; the continuity between the nuchal and dorsal vertebrae in the trunk; tail base and caudal-most portion of the neck; the continuity between the nuchal and dorsal osteoderms in Gavialis gangeticus; and the inability of large, adult individuals of this species to flex the head ventrally osteoderms in Gavialis gangeticus; and the inability of large, adult individuals of this species to flex the head ventrally against the neck to the degree observed in other taxa. against the neck to the degree observed in other taxa. These differences mean that the operational repertoire associated with the bracing system of G. gangeticus is less These differences mean that the operational repertoire associated with the bracing system of G. gangeticus is less diverse than that of other extant crocodilians. For this reason, it is proposed that two distinct forms should be recognised diverse than that of other extant crocodilians. For this reason, it is proposed that two distinct forms should be recognised within the eusuchian-type bracing system: the Gavialis-form and the Crocodylus/Alligator-form. within the eusuchian-type bracing system: the Gavialis-form and the Crocodylus/Alligator-form. The Mysterious Crocodylid Integumentary Sense Organs: The Mysterious Crocodylid Integumentary Sense Organs: What Are They For? What Are They For? Kate Jackson Kate Jackson In all crocodylids and gavialids, a single dark dot is present on each of the ventral scales. Alligatorids lack this In all crocodylids and gavialids, a single dark dot is present on each of the ventral scales. Alligatorids lack this structure. Morphological study has shown this structure to be a sensory organ, similar in morphology to the structure. Morphological study has shown this structure to be a sensory organ, similar in morphology to the mechanosensory “touch papillae” that are present on the facial scales of all crocodilians. Here I describe experiments mechanosensory “touch papillae” that are present on the facial scales of all crocodilians. Here I describe experiments completed and experiments in progress to test the possible function of these integumentary sense organs (ISOs). In completed and experiments in progress to test the possible function of these integumentary sense organs (ISOs). In particular I explore the possibility that they may be osmoreceptors, used for distinguishing hyperosmotic seawater particular I explore the possibility that they may be osmoreceptors, used for distinguishing hyperosmotic seawater from fresh water, similar to many other anatomical and physiological specialisations that make crocodylids better from fresh water, similar to many other anatomical and physiological specialisations that make crocodylids better able to tolerate estuarine conditions than alligatorids. able to tolerate estuarine conditions than alligatorids. 394 394 Status of the American Alligator (Alligator mississippiensis) in Southern Florida, Status of the American Alligator (Alligator mississippiensis) in Southern Florida, USA and its Role in Measuring Restoration Success in the Everglades USA and its Role in Measuring Restoration Success in the Everglades Kenneth G. Rice1, Frank J. Mazzotti2 and Laura A. Brandt3 Kenneth G. Rice1, Frank J. Mazzotti2 and Laura A. Brandt3 1United States Geological Survey, Center for Water and Restoration Studies, University of Florida 1United States Geological Survey, Center for Water and Restoration Studies, University of Florida Field Station, 3205 College Ave., Fort Lauderdale, Florida 33314, USA (ken g [email protected]); Field Station, 3205 College Ave., Fort Lauderdale, Florida 33314, USA (ken g [email protected]); 2University of Florida Fort Lauderdale Research and Education Center, 3205 College Ave., 2University of Florida Fort Lauderdale Research and Education Center, 3205 College Ave., Fort Lauderdale, Florida 33314, USA ([email protected]); Fort Lauderdale, Florida 33314, USA ([email protected]); 3U.S. Fish and Wildlife Service, Arthur R. Marshall Loxahatchee National Wildlife Refuge, 10216 Lee 3U.S. Fish and Wildlife Service, Arthur R. Marshall Loxahatchee National Wildlife Refuge, 10216 Lee Road, Boynton Beach, Florida 33437, USA ([email protected]) Road, Boynton Beach, Florida 33437, USA ([email protected]) Abstract Abstract The American alligator (Alligator mississippiensis) was abundant throughout the pre-drainage Everglades of Southern The American alligator (Alligator mississippiensis) was abundant throughout the pre-drainage Everglades of Southern Florida, USA. Development and water management practices have reduced the spatial extent and changed the Florida, USA. Development and water management practices have reduced the spatial extent and changed the hydropatterns of these habitats. As a result of these activities, alligator populations have decreased. Currently, restoration hydropatterns of these habitats. As a result of these activities, alligator populations have decreased. Currently, restoration of hydrologic pattern and ecological function is beginning in the Everglades. Due to the alligator’s ecological of hydrologic pattern and ecological function is beginning in the Everglades. Due to the alligator’s ecological importance and sensitivity to hydrology, salinity, habitat and system productivity, the species was chosen as an importance and sensitivity to hydrology, salinity, habitat and system productivity, the species was chosen as an indicator of restoration success. A number of biological attributes (relative density, relative body condition, nesting indicator of restoration success. A number of biological attributes (relative density, relative body condition, nesting effort, and nesting success) can be measured, standard methods for monitoring have been developed, and historical effort, and nesting success) can be measured, standard methods for monitoring have been developed, and historical information exists for alligator populations in the Everglades. These attributes can be used as success criteria at information exists for alligator populations in the Everglades. These attributes can be used as success criteria at different spatial and temporal scales and to construct ecological models used for predicting restoration effects. different spatial and temporal scales and to construct ecological models used for predicting restoration effects. Introduction Introduction The American alligator once occupied all wetland habitats in south Florida, from sinkholes and ponds in pinelands to The American alligator once occupied all wetland habitats in south Florida, from sinkholes and ponds in pinelands to mangrove estuaries during periods of freshwater discharge (Craighead 1968; Simmons and Ogden 1998). Development mangrove estuaries during periods of freshwater discharge (Craighead 1968; Simmons and Ogden 1998). Development and water management practices have reduced the spatial extent and changed the hydropatterns of these habitats and water management practices have reduced the spatial extent and changed the hydropatterns of these habitats (Fig. 1; Mazzotti and Brandt 1994). Less freshwater moves through the tributaries into the mangrove zone resulting (Fig. 1; Mazzotti and Brandt 1994). Less freshwater moves through the tributaries into the mangrove zone resulting